vaporous
Vaporous (adj) means relating to vapour, or having the qualities or texture of vapour.
Etymology
Came into English via Middle English vaporous, from Late Latin vapōrōsus (“full of steam”), from Latin vapor (“exhalation; smoke; steam, vapour”), possibly related to Proto-Indo-European *kwep- (“to boil; to smoke, steam; aroma; strong odour”), plus -ōsus (a suffix meaning ‘full of, overly, prone to’, forming adjectives from nouns). The English word can be analysed as vapour + -ous, and is possibly a doublet of hope. Cognates include French vaporeux (“misty, vaporous; filmy, transparent”), Italian vaporoso (“flimsy, gauzy; fluffy; vaporous”), Portuguese vaporoso, and Spanish vaporoso (“airy; vaporous”).