noun
A longitudinal ridge or projection like the keel of a boat.
(botany) Part of a papilionaceous flower consisting of two petals, commonly united, which encloses the organs of fructification.
(botany) The keel of the glume of grasses.
(botany) The principal nerve of a sepal.
(ornithology) The keel of the breastbone of birds.
(anatomy) Any of several features that have a projecting central ridge.