VAPOROUS

miasmal, miasmic, vaporous, vapourous

(adjective) filled with vapor; “miasmic jungles”; “a vaporous bog”

vaporific, vapourific, vaporish, vapourish, vaporous, vapourous

(adjective) resembling or characteristic of vapor; “vaporous clouds”

diaphanous, filmy, gauzy, gauze-like, gossamer, see-through, sheer, transparent, vaporous, vapourous, cobwebby

(adjective) so thin as to transmit light; “a hat with a diaphanous veil”; “filmy wings of a moth”; “gauzy clouds of dandelion down”; “gossamer cobwebs”; “sheer silk stockings”; “transparent chiffon”; “vaporous silks”

Source: WordNet® 3.1

Etymology

Adjective

vaporous (comparative more vaporous, superlative most vaporous)

Relating to vapour; misty, foggy, obscure, insubstantial

So whosoever shall entertain high and vaporous imaginations, instead of a laborious and sober inquiry of truth, shall beget hopes and beliefs of strange and impossible shapes.

Source: Wiktionary

Va"por*ous, a. Etym: [L. vaporosus: cf. vaporeux.]

1. Having the form or nature of vapor. Holland.

2. Full of vapors or exhalations. Shak. The warmer and more vaporous air of the valleys. Derham.

3. Producing vapors; hence, windy; flatulent. Bacon. The food which is most vaporous and perspirable is the most easily digested. Arbuthnot.

4. Unreal; unsubstantial; vain; whimsical. Such vaporous speculations were inevitable. Carlyle.

Source: Webster’s Unabridged Dictionary 1913 Edition