bilge

Concise Oxford English Dictionary © 2008 Oxford University Press:
bilge/bɪlʤ/

▶noun

• 1 the area on the outer surface of a ship's hull where the bottom curves to meet the vertical sides.

  ■ (bilges) the lowest internal portion of the hull.

  ■ (also bilge water) dirty water that collects inside the bilges.

• 2 informal nonsense; rubbish.

▶verb archaic break a hole in the bilge of (a ship).

– origin C15: prob. a var. of bulge.