Meaning

verb support from beneath

verb support with evidence or authority or make more certain or confirm

originEtymology tree Proto-Indo-European *h₁én Proto-Indo-European *h₁entér Proto-Indo-European *(H)n̥dʰí Proto-Indo-European *-ér Proto-Indo-European *(H)n̥dʰér Proto-Germanic *under Proto-West Germanic *undar Old English under- Middle English under- English under- Proto-Germanic *pinnaz Proto-West Germanic *pinn Old English pinn Middle English pinne English pin English underpin From under- + pin.

Etymology from Wiktionary, CC BY-SA 3.0