THESAURUS
Suspect
a bit thick, a bit thin, absurd, account as, accused, arguable, assume, at issue, awake a doubt, be afraid, be diffident, be doubtful, be dubious, be possessive, be skeptical, be uncertain, believe, beyond belief, call in question, challenge, conceive, conclude, confutable, conjectural, consider, contest, contestable, contested, controversial, controvertible, correspondent, daresay, debatable, deduce, deem, defendant, deniable, disbelieve, disbelieved, discredited, disputable, dispute, disputed, distrust, divine, doubt, doubtable, doubted, doubtful, dream, dubious, dubitable, esteem, estimate, expect, exploded, fancy, feel, gather, grant, greet with skepticism, guess, half believe, harbor suspicions, hard of belief, hard to believe, have a feeling, have a hunch, have an idea, have an impression, have an inkling, have reservations, have the idea, hold, hold as, iffy, imagine, implausible, in dispute, in doubt, in dubio, in question, inconceivable, incredible, infer, judge, let, let be, libelee, look upon as, maintain, misdoubt, misgive, mistakable, mistrust, mistrusted, moot, not deserving belief, open, open to doubt, open to question, open to suspicion, opine, passing belief, prefigure, preposterous, presume, presuppose, presurmise, prisoner, problematic, provisionally accept, query, question, questionable, questioned, raise a question, reckon, refutable, regard, repute, respondent, ridiculous, say, scruple, sense, set down as, shadowy, shady, shaky, smell a rat, speculative, staggering belief, suppose, suppositional, surmise, suspected, suspicion, suspicious, take, take for, take for granted, take it, take to be, tall, theorize, thick, thin, think, throw doubt upon, treat with reserve, trow, unbelievable, uncertain, unclear, unconvincing, under a cloud, under suspicion, understand, unearthly, ungodly, unimaginable, unthinkable, unworthy of belief, view as, ween
ROGET THESAURUS
Suspect
Doubt
VB
disbelieve, discredit, not believe, misbelieve, refuse to admit, refuse to believe, doubt, be doubtful, doubt the truth of, be skeptical as to, diffide, distrust, mistrust, suspect, smoke, scent, smell a rat, have doubts, harbor doubts, entertain doubts, suspicions, have one's doubts, demure, stick at, pause, hesitate, scruple, stop to consider, waver, hang in suspense, hang in doubt, throw doubt upon, raise a question, bring in, call in question, question, challenge, dispute, deny, cavil, cause a doubt, raise a doubt, start a doubt, suggest a doubt, awake a doubt, make suspicion, ergotize, startle, stagger, shake one's faith, shake one's belief, stagger one's faith, stagger one's belief.
N
unbelief doubt, unbelief, disbelief, misbelief, discredit, miscreance, infidelity, dissent, change of opinion, retraction, doubt, skepticism, scepticism, misgiving, demure, distrust, mistrust, cynicism, misdoubt, suspicion, jealousy, scruple, qualm, onus probandi, incredibility, incredibleness, incredulity, doubter, skeptic, cynic, unbeliever, unbelieving, skeptical, sceptical, incredulous as to, skeptical as to, distrustful as to, shy as to, suspicious of, doubting, doubtful, disputable, unworthy of, undeserving of belief, questionable, suspect, suspicious, open to suspicion, open to doubt, staggering, hard to believe, incredible, unbelievable, not to be believed, inconceivable, impossible, fallible, undemonstrable, controvertible, cum grano salis, with a grain of salt, with grains of allowance, fronti nulla fides, nimium ne crede colori, timeo Danaos et dona ferentes, I fear the Greeks even when bearing gifts, beware of Greeks bearing gifts, credat Judaeus Apella, let those believe who may, ad tristem partem stenua est suspicio.
Supposition
VB
suppose, conjecture, surmise, suspect, guess, divine, theorize, presume, presurmise, presuppose, assume, fancy, wis, take it, give a guess, speculate, believe, dare say, take it into one's head, take for granted, imagine, put forth, propound, propose, start, put a case, submit, move, make a motion, hazard out, throw out a suggestion, put forward a suggestion, put forward conjecture, allude to, suggest, hint, put it into one's head, suggest itself, run in the head, marvel if, wonder if, wonder whether.