(a.) That may not be trusted; not worthy of trust; unfaithful.

Humean Pyrrhonic a bit thick a bit thin absurd agnostic ambitendent ambivalent amoral arguable at issue at loose ends beguiling beyond belief capricious catchy changeable confutable conjectural conscienceless contestable controversial controvertible corrupt corrupted criminal crooked dark debatable deceiving deceptive delusive delusory deniable devious dishonest dishonorable disinclined disputable distrustful double-minded doubtable doubtful doubting dubitable equivocal evasive fallacious FALSE felonious fence-sitting fence-straddling fickle fishy fly-by-night fraudulent from Missouri hallucinatory hard of belief hard to believe hardly possible hesitant iffy ill-got ill-gotten illusive illusory immoral implausible improbable in dispute in doubt in dubio in question inconceivable incredible incredulous indecisive indirect infirm of purpose insecure insidious irresolute irresolved leery mercurial misleading mistakable mistrustful mistrusting moot more than doubtful mugwumpian mugwumpish mutable not deserving belief not kosher of two minds open open to doubt open to question open to suspicion passing belief preposterous problematic questionable questioning refutable reluctant ridiculous rocky rotten scrupulous shady shaky shameless shifty shy sinister skeptic skeptical slippery speculative staggering belief suppositional suspect suspecting suspicious tall thick thin tottery treacherous trickish tricksy tricky trustless unbelievable uncertain unclear unconscienced unconscientious unconscionable unconvincing undecided undependable underhand underhanded undetermined unearthly unethical ungodly unhealthy unimaginable unlikely unpredictable unprincipled unpromising unreliable unresolved unsafe unsavory unscrupulous unsettled unsound unstable unsteady unstraightforward unsure unthinkable untrusting untrustworthy untrusty unworthy of belief wary without remorse without shame