airy
bodiless
bubbly
downy
ethereal
featherweight
feathery
fluffy
foamy
frothy
gossamery
immaterial
impalpable
imponderable
imponderous
incorporeal
insubstantial
intangible
leger
light
light as air
lighter than vanity
lightweight
mousse
nonsubstantial
souffle
unconcrete
unheavy
unsolid
unsubstanced
unsubstantial
volatile
yeasty
airless
catatonic
colourless
defenseless
dumbfounded
frictionless
impervious
invulnerable
lifeless
light-headed
lightless
nonexistent
pitch-black
sexless
sightless
unable
unbreakable
undetectable
unharmed
unheard
unrecognizable
unsure
untouchable
valueless