implausible

adjective

Difficult to believe; not plausible.

Not plausible; not having the appearance of truth or credibility; of dubious aspect.

adjective

Not plausible; not wearing the appearance of truth or credibility, and not likely to be believed.

adjective

Not plausible; unlikely; dubious.

adjective

having a quality that provokes disbelief

adjective

highly imaginative but unlikely