Longman Dictionary of Contemporary English
water vapour
noun
EXAMPLES FROM CORPUS
▪ Water vapour is a naturally occurring greenhouse gas but the amount of water vapour in the atmosphere is affected by human activities.
▪ Both ordinary and thermal plasterboard are also available with a backing film which makes it resistant to water vapour.
▪ But water vapour is also a greenhouse gas.
▪ Incidentally, cavity wall insulation should be impermeable to water vapour, or interstitial condensation can occur.
▪ It must also provide a high level of water vapour resistance.
▪ Or will more water vapour feed the warming process?
▪ The amount of water vapour in a battery depends on the concentration of sulphuric acid in the solution.
▪ The platinum catalyses the reaction of carbon monoxide and hydrocarbons with air to give carbon dioxide and water vapour.
Wiktionary
water vapour
n. (alternative spelling of water vapor English)
WordNet
water vapour
n. water in a vaporous form diffused in the atmosphere but below boiling temperature [syn: water vapor]