From Middle English mightsomen, mihtsomen, apparently an alteration of Middle English nuhtsumen, from Old English ġenyhtsumian ("to abound, have abundance, suffice"), from Proto-Germanic *ganuhtsumōną ("to suffice"), from *nuhtiz, from Proto-Indo-European *eneḱ-, *neḱ-. Cognate with Old High German ginuhtsamōn ("to be sufficient").