boss2

 
Pronunciation: /bɒs/

noun

  • 1a stud on the centre of a shield.
  • Architecture an ornamental carving covering the point where the ribs in a vault or ceiling cross.
  • the central part of a propeller.
  • 2 Geology a large mass of igneous rock protruding through other strata.

Origin:

Middle English: from Old French boce, of unknown origin