Definition from Wiktionary, the free dictionary
- (intransitive, nautical) Of a vessel: to roll so far on its side that it cannot recover; to capsize or turn turtle.
- (intransitive, idiomatic) To collapse in a faint; to black out; to die.
- We should all go inside, before somebody keels over from the heat.
of a vessel: to roll so far on its side that it cannot recover