Middle English founden, borrowed from Anglo-French fonder, funder, going back to Latin fundāre, derivative of fundus "bottom, base, foundation" — more at bottom entry 1
Verb
borrowed from Middle French fondre "to melt, cast," going back to Old French, going back to Latin fundere "to pour, shed, cast, send forth, disperse," going back to Indo-European *ǵhu-n-d-, present tense derivative of *ǵheu̯d- "pour" (also Germanic, in Old English gēotan "to pour, shed," Old High German giozan, Old Norse gjóta "to drop, throw, give birth [of animals]," Gothic giutan "to pour"), extended form of Indo-European *ǵheu̯- "pour," whence Greek chéō, cheîn "to pour, shed," Tocharian B kewu "I will pour," Sanskrit juhoti "(s/he) pours, sacrifices"