square
straight
artless
bluff
blunt
born yesterday
candid
childlike
confiding
credulous
dependent
depending
direct
frank
ingenu
ingenuous
innocent
naive
naïve
open
openhearted
outspoken
plain
reliant
relying
simpl
simple
simplehearted
simpleminded
sincere
single-hearted
single-minded
trustful
trusting
trusty
unaffected
unassumed
unassuming
unbeguileful
unbeguiling
uncalculating
undeceitful
undeceiving
undeceptive
undesigning
undisguised
undisguising
undissembling
undissimulated
undissimulating
unfeigned
amiable
docile
inoffensive
lovable
truthful
unselfish
unsophisticated
unsuspecting
untroubled