(a.) Having the nature of a problem; not shown in fact; questionable; uncertain; unsettled; doubtful.

a bit thick a bit thin absurd arguable at issue baffling bewildering beyond belief bothering confounding confusing confutable conjectural contestable controversial controvertible debatable deniable discomposing disconcerting dismaying disputable distracting disturbing doubtable doubtful dubious dubitable embarrassing enigmatic hard of belief hard to believe iffy implausible in dispute in doubt in dubio in question inconceivable incredible intricate mistakable moot mysterious mystifying not deserving belief open to doubt open to question open to suspicion passing belief perplexing perturbing preposterous problematic puzzling questionable refutable ridiculous speculative staggering belief suppositional suspect suspicious tall thick thin unbelievable unconvincing unearthly ungodly unimaginable unthinkable unworthy of belief upsetting