n. & v.
n. 1 the lengthwise timber or steel structure along the base of a ship, airship, or some aircraft, on which the framework of the whole is built up. 2 poet. a ship. 3 a ridge along the breastbone of many birds; a carina. 4 Bot. a prow-shaped pair of petals in a corolla etc.
v. 1 (often foll. by over) a intr. turn over or fall down. b tr. cause to do this. 2 tr. & intr. turn keel upwards. keelless adj.
[ ME kele f. ON kjölr f. Gmc ]