implausible

adj

Etymology: Etymology tree Proto-Indo-European *né Proto-Indo-European *n̥- Proto-Italic *n̥- Latin in-bor. Middle English in- English im- English plausible English implausible From im- + plausible.

1. Not plausible; unlikely; dubious.

   “Harper finds the idea that Latin developed into the modern Romance languages too implausible to believe.”