adjective
1.
Synonyms: improbable 1, doubtful, dubious, unlikely
Antonyms: unquestionable
2.
Synonyms: moot , arguable, debatable, disputable, doubtful, dubious, mootable, problematic, uncertain
Related Word: refutable; equivocal, obscure, vague
Contrasted words: dependable, true, trustworthy, trusty; genuine, indubitable, real, undoubted, undubitable, veritable, very
Antonyms: authoritative; unquestionable, unquestioned
3.
Synonyms: unreliable 1, dubious, fly-by-night, trustless, undependable, unsure, untrustworthy, untrusty