Definition of harden in English:



  • 1Make or become hard or harder.

    [no object] ‘wait for the glue to harden’
    [with object] ‘bricks which seem to have been hardened by firing’
    • ‘They include any type of oil or fat that hardens when cold.’
    • ‘These are essential for keeping fat and water dispersed evenly in an emulsion, and then binding the free water after freezing and hardening so ice crystal formation is negligible.’
    • ‘As the crystals form connections, the concrete stiffens, hardens, and gains strength.’
    • ‘The glue-on patches have been just as ineffective, with most failures coming when the glue hardens and cracks and the patch peels away.’
    • ‘Don't bother trying to resist Jim Garrahy's Fudge Kitchen, where the fudge is made in front of you, spread out on a huge marble slab and left to harden before being passed around for sampling.’
    • ‘If the weather warms up the pitch will harden and produce variable bounce,’ says Charles Downes.’
    • ‘Linseed oil putty is used because when it hardens, it contributes to the structure of the window.’
    • ‘Thermoplastics, which soften when heated and harden when cooled, run the gamut from commodity to engineering plastics.’
    • ‘The MIT team made the tags by randomly mixing microscopic glass spheres into transparent epoxy and then hardening the glue into wafers about the size of Chiclets.’
    • ‘Instead of being mixed with liquid, they are mixed with a rubbery material that stays rubbery and doesn't harden like glue.’
    • ‘Tung oil will harden, not stay soft and oily as the typical oil finish you mention.’
    • ‘Heather has coped with a genetic disorder which thickens and hardens her bones and Tom gained his award for rescuing his toddler sister from drowning.’
    • ‘I have seen soft teeth harden after cod liver oil and lots of butter are added to the diet.’
    • ‘The Brazilian Rosewood oil penetrates wood, hardening and protecting individual fibers.’
    • ‘Since Wegener's day, scientists have mapped and explored the great system of oceanic ridges, the sites of frequent earthquakes, where molten rock rises from below the crust and hardens into new crust.’
    • ‘These oils harden when exposed to air and seal the wood.’
    • ‘The outside would immediately harden, but the inside would remain soft.’
    • ‘But this extra water doesn't just sit there as the concrete hardens; it moves through the concrete to an exposed surface and evaporates.’
    • ‘This isn't as much of a concern in the winter months, when the ground freezes over and hardens.’
    • ‘If it hardens in the firing pin hole, we may have to use a Dremel tool and a pick to get it out.’
    solidify, set, become hard, become solid, congeal, clot, coagulate, stiffen, thicken, cake, freeze, bake, crystallize
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    1. 1.1Make or become more severe and less sympathetic.
      [with object] ‘she hardened her heart’
      • ‘They'll trumpet their exemplar's views when he says too much gothic severity hardens the heart, but probably don't care to publicise such statements as this.’
      • ‘The mood among the high command of the Israel Defence Forces and the soldiers battling on the streets hardened.’
      • ‘Within the airline, attitudes appear to be hardening considerably.’
      • ‘My heart should not be hardening against him but it has and yet it feels like porcelain and as if it is starting to crack.’
      • ‘War hardens hearts, eats the economy, and cramps political liberty.’
      • ‘Jeff Leighton, FBU Executive Council member for the Yorkshire region, said there was no doubt attitudes had continued to harden since the strike began.’
      • ‘They had been rejected, first, by the father of the child and then by a number of people who, after giving them shelter, eventually hardened their hearts and turned them out.’
      • ‘A glut of sob stories, short memories and disenchantment over aid funds will create a backlash that hardens people's hearts toward tragedy.’
      • ‘If the truth be told, Biskind doesn't sound all that hardened to it.’
      • ‘An instant later her eyes seemed to harden and become as hard and cold as the rock whose color they took.’
      • ‘Drivers' expressions harden and freeze as ruts deepen, mud thickens and the suspicion dawns that 4WD may not after all be the complete antidote to the laws of gravity and friction, but still they press on.’
      • ‘As the scale of the deal struck with the PDs emerges, that resentment is hardening.’
      • ‘But I will say this: if this conflict should widen, or go on much longer than anticipated, I have little doubt that public support will only harden.’
      • ‘Softly the wind blew his wispy hair, and his cheeks hardened, the shadows falling down as the sun set farther into the sky.’
      • ‘Pro-Agreement loyalists in north Belfast report that attitudes are hardening.’
      • ‘You could feel the concern across the house about what action will be taken and the effect that it may have - but you could also sense that people were bracing themselves and hardening their hearts for tough decisions and a very long haul.’
      • ‘Over the years of life I had hardened my heart with hatred and mistrust.’
      • ‘Once again, the Labour Court has intervened in a bid to resolve the issues, but the trades unions' attitude to flotation is hardening.’
      • ‘He looks as if he wants to speak, but then his eyes harden as she remains impassive.’
      • ‘The opening line was, ‘Immigration, it seems, hardens hearts and softens brains like few other issues’.’
      toughen, desensitize, inure, make insensitive, make tough, make unfeeling, case-harden, harden someone's heart
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    2. 1.2Make or become tougher and more clearly defined.
      [no object] ‘suspicion hardened into certainty’
      [with object] ‘this served only to harden the resolve of the island nations’
      • ‘His eyes hardened into bright emeralds and… I could be imagining it, but they had a somewhat reproachful gleam.’
      • ‘The Tories seem to believe that they can harden up their core support through scapegoating.’
      • ‘He wasn't terribly popular in our part of the constituency and rumours, some of which have hardened into allegations, abounded.’
      • ‘Its pure white heart of snow often is hardened into grey and traitorous sleet.’
      • ‘The spectacle has now hardened into tradition.’
      • ‘And those opinions hardened into a kind of religious conviction beyond change when Hoddle left England in 1987.’
      • ‘The generalised irreverence of his earlier films has hardened into a focused attack on the equal absurdities of war and the British class system.’
      • ‘With the Lebanese government balking at an international investigation into the murder, tensions are rising and positions hardening.’
      • ‘The country has long since hardened into its own shape, and whether it holds together or breaks into pieces is largely up to the Iraqis who now have it in their hands.’
      • ‘He did this to harden up electoral support and build a core of activists committed not just to racism, but to fascism.’
      • ‘The US has hardened into two virulently opposed ideological and cultural camps that are almost equal in numbers.’
      • ‘The lightness of the first film had hardened into a frantic, unpleasant quality - it's easily the worst of the series.’
      • ‘It defends faith by preventing it from being hardened into abstractions.’
      • ‘His heart froze into muddy ice and his eyes hardened into a wide glance.’
      • ‘A surprised burst of laughter softened Adrienne's face before it hardened into familiar lines.’
      • ‘As far as the office itself is concerned, companies have to break away from their traditional reliance on the perimeter firewall and look to harden up defences from within.’
      • ‘The problem is not that America has hardened into red states and blue ones.’
      • ‘They see that his supporters are hardening in their views but not increasing their numbers.’
      • ‘No doubt plenty of people will harden in their support for the Democrats in the next election.’
      • ‘Michael Howard has finally stopped wittering on about immigration after discovering that this is hardening up the Labour support.’
      toughen, desensitize, inure, make insensitive, make tough, make unfeeling, case-harden, harden someone's heart
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    3. 1.3[no object](of prices of shares, commodities, etc.) rise and remain steady at a higher level.
      ‘if oil prices harden at the end of this century’
      • ‘Regardless, companies would be wise to let others take the initial plunge for at least six months while XP hardens in the marketplace.’
      • ‘The commercial insurance market is hardening, as they say in the insurance business.’
      • ‘He said ‘As the prospects of a bumper EU harvest fade rapidly due to adverse weather conditions, market prices for grain will harden.’’
      • ‘This boom has been fuelled by the Indian shipping rates which are an all time high due to tonnage charges hardening in the international market.’
      • ‘‘This is evident in a number of markets where rents are falling, but yields are not only holding steady, but in most instances hardening,’ he said.’
      • ‘ICICI's chief executive officer K.V.Kamath said that in spite of steel prices hardening globally, ICICI will not lend any further to the industry.’
      • ‘‘By the time the standards harden, we have something that has been used by a lot of people,’ said Bob Sutor, IBM's director of e-Business strategy.’
      • ‘Record low yields are being set this year, and yields will harden further for the foreseeable future.’
      • ‘Property in Switzerland is becoming more popular with British skiers, as the French market hardens and becomes more expensive.’
      • ‘Bord Gáis has not hiked prices by anything like that amount to the consumer, but it is coming under increasing pressure due to the hardening of prices on the wholesale market in Britain.’
      • ‘Similarly, the authors of a number of country case studies report evidence of greater wage and price flexibility with the hardening of the exchange rate commitment.’
      • ‘The latest polling evidence suggests that while opposition to Britain joining the euro is hardening, popular support for the UK staying in membership of the European Union is at its strongest in nearly a decade.’
      • ‘Tighter supplies of beef cattle in the midlands and northern regions of the country has led to a further hardening on prices for this weeks kill.’
      • ‘Goldman Sachs believes oil prices are continuing to harden and that buying at $55 per barrel forward offers huge potential gains to investors.’
      • ‘However, this is looking increasingly unrealistic as the view hardens that a sustained DRAM price recovery must happen for the PC industry's traditional uptick period to start in September.’
      • ‘The market is hardening all the time and I feel it will remain active over the coming months,’ said Stanley.’
      • ‘Trade has kept pretty steady over the past week, with lamb prices hardening in response to smaller numbers on the market.’
      • ‘Harper puts great stock in the role of insurance as a way of both incentivizing efficient levels of target hardening and of coping with the risks of loss from such events.’
      • ‘Consequently less speculative accommodation is now being provided, which we believe will lead to rents hardening and a build-to-suit market becoming more preeminent.’
      • ‘Lamb prices are still holding pretty steady, with the odd sign they might be hardening.’


  • hardening of the arteries

    • another term for arteriosclerosis
      • ‘The results of this type of thinking include diabetes, hypertension, hardening of the arteries, premature senility, arthritis, liver disease and a whole host of other conditions that you do not want.’
      • ‘It interferes with daily activities and is present in about a quarter of the people who have hardening of the arteries in the legs.’
      • ‘Smoking promotes a process called atherosclerosis, or hardening of the arteries, and this is one of the causes of stroke.’
      • ‘Hypertension can cause heart failure, hardening of the arteries (and potential heart attack), kidney failure, vision changes, or stroke.’
      • ‘Well, yes there is increasing evidence, for example, that inflammation is intimately involved and not only in common forms of arthritis, but also in heart disease, hardening of the arteries, heart attacks and so on.’
      • ‘In the REVERSAL study, Lipitor halted the progression of atherosclerosis, or hardening of the arteries, while the other statin merely slowed progression.’
      • ‘The Atherosclerosis Risk in Communities Study is a long-term, multicenter investigation in four U.S. communities of factors associated with hardening of the arteries and how that illness progresses.’
      • ‘These changes include the graying and loss of hair, cataract formation, hardening of the arteries, osteoporosis, diabetes, skin changes, and cancer.’
      • ‘In atherosclerosis, also called hardening of the arteries, deposits of fatty substances, cholesterol, calcium and other substances build up in the inner lining of an artery.’
      • ‘Even Bill Clinton, who exercised, started eating a healthier diet and got presidential level medical care for eight years, can fall prey to relentless arteriosclerosis, or hardening of the arteries.’

Phrasal Verbs

  • harden something off

    • Inure a plant to cold by gradually increasing its exposure to it.

      ‘the cuttings can be left in the frame until mid May, when they can be hardened off and planted out’
      • ‘A week or so before transplanting outdoors, harden them off, stop fertilizing and watering, and put plants outside each day to help them adjust to new growing conditions.’
      • ‘Add moisture retaining granules and slow release fertiliser to the compost and gradually harden the plants off before putting them outside completely at the end of the month.’
      • ‘Gradually harden them off over three to five days by putting them in a protected shady spot, first for half a day, then a full day, and then gradually into full sun.’
      • ‘First the seedlings are hardened off by moving them outside in the flats for an hour or two the first day and increasing the time until, in a week, they stay out around the clock.’
      • ‘Don't put them outdoors, though, until all danger of frost has passed, and remember to harden them off properly.’
      • ‘I hardened it off for growing outside and transferred the whole lot into a large, blue glazed pot.’
      • ‘Not everyone has the luxury of a greenhouse, but plants can be hardened off by taking them outdoors during the day and bringing them in again in the late evening.’
      • ‘Eggplants are very sensitive to transplant shock, so take extra care to harden them off properly.’
      • ‘We've hardened the turf off with some high-potassium fertilizers and tried to keep any water on the surface of the greens to a minimum.’
      • ‘Place them out of direct sun on a light windowsill or in the greenhouse to grow on until they can be hardened off and planted out at the end of May.’