Im‐plau″si‐ble (?), a. [Pref. im- not + plausible: cf. F. implausible.] Not plausible; not wearing the appearance of truth or credibility, and not likely to be believed. “Implausible harangues.” Swift.
— Im‐plau″si‐ble‐ness, n. — Im‐plau″si‐bly, adv.