Meaning

noun a projection or ridge that suggests a keel

noun the median ridge on the breastbone of birds that fly

noun one of the main longitudinal beams (or plates) of the hull of a vessel; can extend vertically into the water to provide lateral stability

originFrom Middle English kelen, from Old English cēlan (“to cool, to make or become cool”), from Proto-West Germanic *kōlijan, from Proto-Germanic *kōlijaną (“to cool”). Cognate with Saterland Frisian käile, köile (“to cool”), Dutch koelen (“to cool”), German Low German köhlen (“to cool”), German kühlen (“to cool”), Danish køle (“to cool”), Icelandic kæla (“to cool”).

Etymology from Wiktionary, CC BY-SA 3.0