dangerous
erratic
fallible
irresponsible
temperamental
uncertain
unsafe
unsound
adrift
afloat
alternating
amorphous
capricious
changeable
changeful
coquettish
desultory
deviable
disreputable
dizzy
doubtful
dubious
eccentric
faddish
faithless
false
falsehearted
fast and loose
fickle
fitful
flickering
flighty
flimsy
flirtatious
flitting
fluctuating
fly-by-night
freakish
garbled
giddy
hazardous
impetuous
impulsive
inaccurate
inauthentic
inconsistent
inconstant
indecisive
inexact
infirm
insecure
insubstantial
irregular
reliable
confuse
dishonest
fallacious
imperfect
inadequate
ineffective
inefficient
mislead
unable
unpredictable
unsatisfactory
unstable
untrustworthy
liable
pliable
undeniable
unjustifiable
unverifiable
viable
constant
trustworthy