Is it ensure, insure, or assure?
early 14c., from Old French fondrer "collapse; submerge, sink, fall to the bottom," from fond "bottom," from Latin fundus "bottom, foundation" (see fund (n.)). Related: Foundered; foundering.
"one who establishes, one who sets up or institutes something," mid-14c., from Anglo-French fundur, Old French fondeor, from Latin fundator, agent noun from fundare (see found (v.1)).
"one who casts metal," c.1400, agent noun from found (v.2).
founder foun·der (foun'dər)
v. foun·dered, foun·der·ing, foun·ders
To stumble, especially to stumble and go lame. Used of horses.
To become ill from overeating. Used of livestock.
To be afflicted with laminitis. Used of horses.