a person who manufactures articles of cast metal; the owner or operator of a foundry

an iron founder

a person who establishes an institution or settlement

he was the founder of modern Costa Rica

(of a ship) fill with water and sink

six drowned when the yacht foundered off the Cornish coast

(of a horse or its rider) stumble or fall from exhaustion, lameness, etc.

some of their horses foundered and damaged themselves in the stones of the riverbed

laminitis in horses, ponies, or other hoofed animals

make (someone) very cold

it would founder you out there

get a fire lit, I'm foundered