devious
fly-by-night
shady
shifty
slippery
tricky
dangerous
desultory
doubtful
dubious
hazardous
inaccurate
infirm
insecure
insincere
insubstantial
irresponsible
perilous
precarious
provisional
questionable
risky
rocky
shaky
shifting
temporary
tentative
ticklish
tottery
treacherous
trustless
unassured
uncertain
undependable
unfaithworthy
unhealthy
unpredictable
unreliable
unsafe
unsolid
unsound
unstable
unsteadfast
unsteady
unsubstantial
unsure
untrusty
amoral
deprave
dishonest
fallacious
fickle
heartless
illogical
improvident
inefficient
perfidious
unfair
unfaithful
unfitted
unprepared
unprincipled
untrue
untruthful
trustworthy
accurate
faithful
reliable
sincere
true