- keel - the median ridge on the breastbone of birds that fly
--1 is a kind of carina
--1 is a part of carinate, carinate bird, flying bird- keel - one of the main longitudinal beams (or plates) of the hull of a vessel; can extend vertically into the water to provide lateral stability
--2 is a kind of beam
--2 is a part of hull
--2 has part: fin keel
--2 has particulars: bilge keel - keel - one of the main longitudinal beams (or plates) of the hull of a vessel; can extend vertically into the water to provide lateral stability