So thin as to transmit light:
— Vaporous silks.

synonyms: cobwebby, diaphanous, filmy, gauze-like, gauzy, gossamer, see-through, sheer, transparent, vapourous.

Roget 334: gaseous, aeriform^†, ethereal, aerial, airy, vaporous, volatile, evaporable^†, flatulent.   

Roget 353: bubbling etc. v.; frothy, nappy^†, effervescent, sparkling, mousseux [Fr.], frothy [Fr.Tr.], up.    cloudy etc. n.; thunderheaded^†; vaporous, nebulous, overcast.    ... show more

Roget 426: opaque, impervious to light; adiaphanous^†; dim etc. 422; turbid, thick, muddy, opacous^†, obfuscated, fuliginous^†, cloud, hazy, misty, foggy, vaporous, nubiferous^†, muggy^† etc. (turbidity) 426.1. smoky, fumid^†, murky, dirty.    ... show more

Roget 426a: turbid, thick, muddy, obfuscated, fuliginous^†, hazy, misty, foggy, vaporous, nubiferous^†; cloudy (cloud) 353.    smoky, fumid^†, murky, dirty.    ... show more

Polish: przeźroczysty, prześwitujący, przezroczysty

Resembling or characteristic of vapor:
— Vaporous clouds.

synonyms: vaporific, vaporish, vapourific, vapourish, vapourous.

Filled with vapor:
— A vaporous bog.

synonyms: miasmal, miasmic, vapourous.