long thick piece of wood or metal or concrete, etc., used in construction | one of the main longitudinal beams (or plates) of the hull of a vessel; can extend vertically into the water to provide lateral stability |
a gymnastic apparatus used by women gymnasts | the median ridge on the breastbone of birds that fly |
the broad side of a ship | a projection or ridge that suggests a keel |
(nautical) breadth amidships | |
a signal transmitted along a narrow path; guides airplane pilots in darkness or bad weather | |
a column of light (as from a beacon) | |
a group of nearly parallel lines of electromagnetic radiation | |