impure
adulterate
airy
attenuate
attenuated
blemished
cut
damaged
debased
defective
deficient
dilute
diluted
erroneous
ethereal
fallible
faulty
fine
flimsy
found wanting
gaseous
immature
impaired
imperfect
imprecise
inaccurate
inadequate
incomplete
inexact
insubstantial
lacking
makeshift
mediocre
mixed
not perfect
off
partial
patchy
rare
rarefied
reduced
short
sketchy
slight
sophisticated
subtile
subtle
tenuous
thin
unadulterated