Synonyms and related words :
a bit thick, a bit thin, absurd, antic, barred, beguiling, bewildering, beyond belief, closed-out, contrary to reason, doubtable, doubtful, dubious, dubitable, enigmatic, exceptional, excluded, extraordinary, fabulous, fanciful, fantastic, fascinating, hard of belief, hard to believe, hopeless, implausible, impossible, incomprehensible, incredible, logically impossible, marvelous, mind-boggling, miraculous, not deserving belief, not possible, open to doubt, open to suspicion, outlandish, overwhelming, oxymoronic, paradoxical, passing belief, passing strange, phenomenal, preposterous, problematic, prodigious, prohibited, puzzling, questionable, rare, remarkable, ridiculous, ruled-out, self-contradictory, sensational, staggering, staggering belief, strange, striking, stupendous, suspect, suspicious, tall, thick, thin, unaccountable, unbelievable, unconvincing, unearthly, unexpected, ungodly, unheard-of, unimaginable, unique, unknowable, unprecedented, unthinkable, unworthy of belief, weak, wonderful, wondrous