"establish," late 13c., from Old French founder (12c., Modern French fonder), from Latin fundare "to lay the bottom or foundation of something," from fundus "bottom, foundation" (see fund (n.)). Related: Founded; founding. Phrase founding fathers with reference to the creators of the American republic is attested from 1916.
"cast metal," late 14c., "to mix, mingle," from Middle French fondre "pour out, melt, mix together," from Old French fondre, from Latin fundere "melt, cast, pour out," from PIE *gheud- (cf. Gothic giutan, German gießen, Old English geotan "to pour"), from root *gheu- "to pour" (cf. Greek khein "to pour," khoane "funnel," khymos "juice"). Meaning "to cast metal" is from 1560s.