Definition of vapour in English:


(US vapor)


  • 1[mass noun] A substance diffused or suspended in the air, especially one normally liquid or solid.

    ‘dense clouds of smoke and toxic vapour’
    [count noun] ‘petrol vapours’
    • ‘You might also add a few drops of the oil to a hot bath and soak for a while, inhaling the steamy vapors.’
    • ‘Having grown up in a cloud of nicotine vapour I am still thankful that I never succumbed.’
    • ‘As water vapor condenses in the air each night, grass, plants and cars are covered by morning with a thin layer of water.’
    • ‘Fire officials say gas station explosions like this are rare, but they can be sparked by static electricity or cell phones igniting the gasoline vapors.’
    • ‘Work should be carried out in a well ventilated area, and ingestion and inhalation of the vapour should be avoided.’
    • ‘When you puff gently on the device, nicotine vapor is released from a cartridge inside the device.’
    • ‘A nebuliser is a device that turns a medicine into an vapour, and is used with a face mask or mouthpiece.’
    • ‘As the warm air rises the water vapor in it condenses into clouds that can produce rain, snow, sleet or freezing rain, often all four.’
    • ‘The vapors are odorless, and victims may not know they have been exposed until symptoms develop.’
    • ‘Watching the steam rise, she inhaled the comforting vapors and decided to take a bath.’
    • ‘However, this type of bleach and its vapors are irritating to the skin, eyes, nose, and throat.’
    • ‘A nebulizer machine turns liquid medicine into a vapor that you breathe.’
    • ‘Adding a few drops of essential oil to a bowl of hot water, or to a warm bath, releases the vapour, which is then inhaled.’
    • ‘Simply fill a mug halfway with boiling water, add three to five drops of eucalyptus essential oil, cup your free hand over your nose and the mug and inhale the vapors for three to five minutes.’
    • ‘Air rising to pass over the mountains cools and the water vapour condenses into cloud, rain and, if it is cold enough, snow.’
    • ‘We learn that the Indians in the Mojave Desert inhaled the vapors from boiling creosote to treat respiratory infections.’
    • ‘Ethyl chloride is a rapid-acting general anesthetic that becomes flammable and explosive when 4 to 15 percent of the vapor is mixed with air.’
    • ‘A few die-hards do start their exercises early, their breath turning to vapour in the cold.’
    • ‘Never ignite vapors from aerosol cans, they can explode.’
    • ‘Mercury vapors can cause toxic effects on the central and peripheral nervous system, lungs, kidneys, skin, and eyes.’
    haze, mist, spray, steam, water vapour, condensation, smoke, fumes, exhalation, fog, smog, murk, cloud, cloudiness, drizzle, dampness, humidity, mistiness, scotch mist
    View synonyms
    1. 1.1Physics [count noun]A gaseous substance that is below its critical temperature, and can therefore be liquefied by pressure alone.
      Compare with gas
      • ‘A vapor is the gaseous phase of a substance that, under ordinary conditions, exists as a liquid or solid.’
      • ‘What results is a super-saturated vapour, which cools to near ambient temperatures in a few milliseconds and condenses into the aerosol particles that make up the smoke.’
      • ‘A gas is distinguished from a vapor in that a gas is above the critical point at which the liquid boils.’
  • 2dated A sudden feeling of faintness or nervousness or a state of depression.

    ‘a fit of the vapours’
    • ‘She sat at the table, legs propped up on the table in a manner that would give ladies in the finer centres of Europe a case of the vapours.’
    • ‘Clark himself - who was so pro-Thatcher he had a fit of the vapours in her presence - was not a fan.’
    • ‘Just stepping outside is enough to give an architectural purist the vapours.’
    • ‘I think I d have loved to be alive in an era of elegance and old-fashioned manners where ladies had attacks of the vapours and the gentlemen were just that - gentlemen.’
    • ‘‘If you have ever got the vapours when your teenager has stood beside your fixed-line phone making an expensive mobile call, then this addresses the problem,’ he said.’
    • ‘Abandoning our corsets would surely prevent the many attacks of the vapours we ladies are prone to!’


  • Talk in a vacuous, boasting, or pompous way.

    ‘he was vapouring on about the days of his youth’
    • ‘Neither of these vaporings has the remotest basis in the actual Constitution.’
    • ‘Beckford later claimed that he suggested to Mozart one of the best-known tunes in The Marriage of Figaro: he may have been ‘vapouring’ like his father.’
    • ‘To listen to the endless vapourings on the broadcast media, you would think there had been an earthquake at Holyrood.’
    • ‘Their coverage was dominated by the self-important vapourings of a stream of politicians.’


Late Middle English: from Old French, or from Latin vapor steam, heat. The current verb sense dates from the early 17th century.