'implausible' originates from Latin, specifically the word 'implausibilis,' where 'in-' meant 'not' and 'plausibilis' meant 'worthy of applause or approval.'

'implausibilis' transformed into the French word 'implausible,' and eventually became the modern English word 'implausible' through Middle English.

Initially, it meant 'not worthy of applause or approval,' but over time it evolved into its current meaning of 'not seeming reasonable or probable.'