v. & n.
v. 1 a intr. (of a ship) fill with water and sink. b tr. cause (a ship) to founder. 2 intr. (of a plan etc.) fail. 3 intr. (of earth, a building, etc.) fall down or in, give way. 4 a intr. (of a horse or its rider) fall to the ground, fall from lameness, stick fast in mud etc. b tr. cause (a horse) to break down, esp. with founder.
n. 1 inflammation of a horse's foot from overwork. 2 rheumatism of the chest-muscles in horses.
[ ME f. OF fondrer, esfondrer submerge, collapse, ult. f. L fundus bottom ]