Meaning of KEEL in English
n. 25B6; noun the upturned keel of the boat : BASE, bottom (side), underside.
25A0; keel over
the boat keeled over : CAPSIZE, turn turtle, turn upside down, founder; overturn, turn over, tip over.
the slightest activity made him keel over : COLLAPSE, faint, pass out, black out, lose consciousness, swoon.
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012