trustful
trusting
artless
bluff
blunt
born yesterday
candid
childlike
confiding
credulous
dependent
depending
direct
doting
easily taken in
easy of belief
fond
frank
guileless
inclined to believe
infatuated
ingenu
ingenuous
innocent
naive
open
openhearted
outspoken
overconfiding
overcredulous
overtrustful
overtrusting
plain
reliant
relying
simple
simplehearted
simpleminded
sincere
single-hearted
single-minded
superstitious
trusty
uncritical
undoubtful
undoubting
unguarded
unreserved
unskeptical
defenceless
forgettable
good-hearted
good-tempered
oblivious
self-possessed
selfless
sinless
tractable
truthful
unaffected
unafraid
unassuming
unembarrassed
unselfish
unstudied
unsuspecting
warm-hearted
distrustful
suspicious