thin as air
- wispyThin and insubstantial
- etherealDelicate beyond earthly measure
- gossamerFilmy, delicate material
- delicateEasily broken or harmed
- vaporousLike a gas, diffuse
insubstantial · fleeting · breath · mist · gauze · transparent · featherlight · dissolving · faint · sheer · fragile · vanishing · weightless · airy · hollow · tenuous · filmy · diaphanous
density/substance
thin as airdense
Closely packed together
solid as a rock · substantial · thick · solid · weighty
credibility/validity
thin as airrock-solid
Utterly firm and reliable
ironclad · airtight · watertight · bulletproof · unassailable
visibility/presence
thin as airplain as day
Unmistakably evident
palpable · tangible · obvious · conspicuous · unmistakable