verb

  • 1Make or become less dense, crowded, or numerous.

    with object ‘the remorseless fire of archers thinned their ranks’
    no object ‘the trees began to thin out’
    ‘thinning hair’
    • ‘The crowd began to thin out so early it looked as if someone had spread a rumor that the police were going to raid the place.’
    • ‘His prodigious belly shrinks and his beard thins.’
    • ‘Unable to resist such a challenge, I waited for the crowd to thin out and finally introduced myself to an attractive woman with a melodious accent.’
    • ‘After a few miles our path curved away from the river, the trees thinned out, and we came upon, wonder of wonders, a proper town.’
    • ‘While they are effective, side effects can include loss of libido and bone thinning.’
    • ‘As their numbers thin out, they turn on each other, in an attempt to figure out who is the killer.’
    • ‘Mini-grafts of hair are harvested from the back of the head and replanted in thinning areas of hair.’
    • ‘To thin out thicker hair and give it a softer finish, Campbell prefers razor cutting over buzz cuts.’
    • ‘But when it comes to the lost causes, the inevitable setbacks, the small defeats, the crowds thin out quickly.’
    • ‘The whiting have started to thin out although the blackfish have picked up a bit.’
    • ‘At first I thought I was just imagining it, but then it became clear that the trees were thinning out.’
    • ‘I have bare patches around the edges and thinning areas in the middle.’
    • ‘They approached the first crossroad and turned right, the road soon becoming smoother and wider as the trees started to thin.’
    • ‘Beyond here, the path dawdles up past imposing villas and more humble caprese dwellings until the houses thin out and the going gets steep.’
    • ‘The celebration continues through Sunday when the crowd begins to thin out.’
    • ‘Perhaps the most telling sign of the night was that the crowd actually started to thin out as their set continued.’
    • ‘As they walked, the ground gradually began to level out and the trees thinned.’
    • ‘We'll open up at 9am and stay open until 3pm or whenever the crowds thin out.’
    • ‘The crowd began to thin out but not so that the bar was entirely empty.’
    • ‘He floats down river in this fashion and before long, the trees begin to thin.’
    become less dense, become less numerous, decrease, diminish, dwindle, lessen, become less in number
    prune, cut back, trim
    View synonyms
    1. 1.1with object Remove some plants from (a row or area) to allow the others more room to grow.
      ‘thin out the rows of peas’
      • ‘The seedlings were later thinned to two plants per pot.’
      • ‘Try growing some in a large clay pot, thinning the seedlings as they grow to just 1 or 2 per pot.’
      • ‘Seven days after planting, the seedlings were thinned to one plant per pot.’
      • ‘You should thin the seedlings until they are about one foot apart.’
      • ‘Seven days after sowing, each pot was thinned to 11 plants.’
      • ‘It is hoped that by thinning the area around the veteran oaks, it will encourage the public to enjoy the view of the trees.’
      • ‘The rule specifically gives the U.S. Forest Service the power to build a road, fight a fire or thin an area to reduce fire risk.’
      • ‘If too many seedlings appear, thin the plants to about 5 inches apart.’
      • ‘Plants were thinned to five plants per pot after seedling emergence.’
      • ‘After germination, seedlings were thinned to five plants per pot.’
      • ‘The plants are best thinned to about 15 inches apart because of their spreading habit.’
      • ‘Do you feel guilty when you have to thin out seedlings?’
      • ‘The plants need to be thinned to about 150 mm apart, unless you want to grow them closer together for young and tender mini-leeks.’
      • ‘Some of the trees have grown so fast that decisions need to be made as to whether they are to be thinned or allowed to develop into copses.’
      • ‘When the tops of the carrots grow thicker, thin them to about two to three inches apart.’
      • ‘Rows were thinned to provide an even plant spacing and each plant marked with a numbered stake.’
      • ‘Another crucial key to success is thinning seedlings, especially those that have broadcast directly into beds.’
      • ‘When your plants start to show a couple of leaves, thin them back a little, then a little more as they get taller, until they're at least eight inches apart.’
      • ‘In all experiments, rows produced by paper-ribbon sowing were thinned to one plant per site immediately after seedling emergence.’
      • ‘The plants were thinned 10-12 days after germination to give an average of 20 plants, uniformly distributed per pot.’
    2. 1.2 Make or become more watery in consistency.
      with object ‘if the soup is too thick, add a little water to thin it down’
      no object ‘the blood thins’
      • ‘Garlic also thins the blood - so be aware it may increase bleeding.’
      • ‘I have had heart bypass surgery and am on medication to thin my blood.’
      • ‘Because vitamin E can thin the blood, high doses might increase the risk of abnormal bleeding.’
      • ‘A side effect common to all anticoagulants is the risk of excessive bleeding, due to the blood being thinned.’
      • ‘Heat through, adding water to thin to desired consistency.’
      • ‘Taking supplements, even vitamin E, known to thin blood, is safe.’
      • ‘Pureed and thinned with a little stock syrup, it makes a coulis to accompany baked lemon cheesecake or a passionfruit mousse.’
      • ‘Although the benefits of ginkgo are not clearly understood, it is believed that it may improve blood flow to the brain by thinning the blood.’
      • ‘The chemical, salicylic acid, is an active ingredient in aspirin, which is known to thin the blood and reduce the risk of heart disease and bowel cancer.’
      • ‘Aspirin has been used to treat heart disease because it thins blood and prevents clots.’
      • ‘This thins the blood and can help to prevent the clot that is blocking the coronary artery from spreading.’
      • ‘Oil paint can be thinned to a watery consistency or brushed on with thick luscious strokes.’
      • ‘Jordan has to take aspirin every day to thin his blood, and has been told he could be on medication for the rest of his life.’
      • ‘Warfarin protects those with heart problems by thinning the blood in order to prevent clotting.’
      • ‘Although these drugs are sometimes called blood thinners, they do not actually thin the blood.’
      • ‘Add enough water to thin the consistency of the dressing so it can be drizzled over salad.’
      • ‘If the policemen had questioned the mother, she could have explained that her son required regular injections to thin his blood because of a thrombosis.’
      • ‘Specialists can diagnose the condition with a simple blood test, and treatment normally includes medication to thin the blood.’
      • ‘Neither would I want to give them large amounts of garlic, which thins blood in a similar way.’
      • ‘Aspirin's ability to thin the blood has led to its use in preventing heart attacks and strokes.’
      dilute, water down, weaken
      View synonyms
  • 2Make or become smaller in thickness.

    with object ‘their effect in thinning the ozone layer is probably slowing the global warming trend’
    • ‘Today Science tells us the speed of light is decaying, the magnetic field is collapsing, the earth is slowly beginning to wobble on its axis, the protective ozone layer is thinning.’
    • ‘The sheet has a maximum thickness of 4 meters at the south end of Flint Ridge State Memorial and an average thickness of 1.5 meters, thinning toward the edges.’
    • ‘This video shows the Antarctic ozone layer thinning during 1998, reaching its thinnest in the southern spring.’
    • ‘The ash is local in occurrence; its maximum thickness is about 1m, but it thins laterally to a few tens of centimetres over about 40 m.’
    • ‘Many doom and gloom headlines often scream about the ozone layer thinning over the poles, and this has given some people the idea that ozone is a harmless gas that protects us from the rays of the sun.’
    • ‘At Kimmeridge 3, the sandstone body maintains its thickness before thinning rapidly toward Southard Quarry.’
    • ‘Over the past 40 years, the Arctic ice pack has thinned and shrunk significantly.’
    • ‘The body reaches a thickness of 80 m at Hagevatnet and thins towards the south.’
    • ‘Since 1978 Arctic sea ice area has shrunk by some 9 percent per decade, and thinned as well.’
    • ‘Posteriorly, the pterygoid thins to less than 1 mm in thickness.’
  • 3Golf
    with object Hit (a ball) above its centre.

    • ‘That was as close to the ball as you can get without thinning it.’
    • ‘The other important moment of his round came soon after noon, when first he mishit his five-iron on the 17th, then thinned the ensuing bunker shot.’
    • ‘The lie was not great and the shot was slightly thinned, the ball finishing as much as 40 feet past the cup.’
    • ‘Disaster strikes when he thins his pitch from the rough beside the 10th green all the way across the putting surface.’