IPA: /ɪmˌplɔːzəˈbɪlɪti/
KK: /ɪmˌplɔːzəˈbɪlɪti/
The quality of being unlikely or difficult to believe.
The implausibility of his story made everyone doubt his honesty.
Implausibility → It is formed from "im-" (meaning not) and "plausibilis" (from Latin, meaning worthy of applause or approval) and the suffix "-ity" (meaning the state or quality of). The word "implausibility" refers to the quality of being not worthy of approval or belief.
Think of something that is 'not' ('im-') 'worthy of approval' ('plausibilis') — that's why implausibility means something that is hard to believe.