Dictionary.com
Thesaurus.com
Synonyms

implausible

American  
[im-plaw-zuh-buhl] / ɪmˈplɔ zə bəl /

adjective

  1. not plausible; not having the appearance of truth or credibility.

    an implausible alibi.
    Synonyms:
    unbelievable, improbable, unlikely
implausible British  
/ ɪmˈplɔːzəbəl /

adjective

  1. not plausible; provoking disbelief; unlikely

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • implausibility noun
  • implausibleness noun
  • implausibly adverb

Etymology

Origin of implausible

First recorded in 1595–1605; im- 2 + plausible

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Aswath Damodaran, the so-called ‘dean of valuation,’ said a popular characterization of a dystopian AI future of displacement and disruption was implausible.

From MarketWatch • Mar. 5, 2026

He said while Tina Smith was "in the thrall of McKenna" it was implausible that she did not know what was happening in McKenna's operations.

From BBC • Feb. 12, 2026

But those implausible sci-fi scenarios, believe it or not, are nowhere near the worst-case possibilities.

From Salon • Jan. 18, 2026

How did this implausible turn of events come to pass?

From Slate • Jan. 13, 2026

Jupiter’s moons made this arrangement rather less implausible than it had seemed.

From "The Invention of Science" by David Wootton

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.