Bilge

Nautical.

either of the rounded areas that form the transition between the bottom and the sides on the exterior of a hull.
Also, bilges. (in a hull with a double bottom) an enclosed area between frames at each side of the floors, where seepage collects.
Also called bilge well. a well into which seepage drains to be pumped away.
Also called bilge water. seepage accumulated in bilges.

Slang. bilge water (def 2).
the widest circumference or belly of a cask.
Nautical.

to leak in the bilge.
(of white paint) to turn yellow.

to bulge or swell out.
Nautical. to damage (a hull bottom) so as to create an entry for seawater.
Historical Examples

The Coast of Adventure Harold Bindloss
Blow The Man Down Holman Day
At Ypres with Best-Dunkley Thomas Hope Floyd
John Splendid Neil Munro
Caleb West, Master Diver F. Hopkinson Smith
Southern Arabia Theodore Bent
The Wreck of the Nancy Bell J. C. Hutcheson
On Yachts and Yacht Handling Thomas Fleming Day
Blow The Man Down Holman Day
Torpedoes and Torpedo Warfare C. W. Sleeman

noun
(nautical) the parts of a vessel’s hull where the vertical sides curve inwards to form the bottom
(often pl) the parts of a vessel between the lowermost floorboards and the bottom
Also called bilge water. the dirty water that collects in a vessel’s bilge
(informal) silly rubbish; nonsense
the widest part of the belly of a barrel or cask
verb
(intransitive) (nautical) (of a vessel) to take in water at the bilge
(transitive) (nautical) to damage (a vessel) in the bilge, causing it to leak
n.