early 14c. "to send to the bottom" (transitive); late 14c., "to sink or fall" (intransitive), from Old French fondrer "collapse; submerge, sink, fall to the bottom" (Modern French fondrier), from fond "bottom" (12c.), from Latin fundus "bottom, foundation" (see fund (n.)). Not especially of ships in Middle English, where it typically meant "fall to the ground." Figurative use from 1580s. Related: Foundered; foundering.
"one who establishes, one who sets up or institutes (something)," mid-14c., from Anglo-French fundur, Old French fondeor "founder, originator" (Modern French fondateur), from Latin fundator, agent noun from fundare "to lay a foundation" (see found (v.1)). Fem. form foundress is from early 15c.; also fundatrix (1540s).
"one who casts metal," c. 1400, agent noun from found (v.2).