Definitions for "bullpen"
an open area in a baseball stadium, off the playing field, where pitchers may warm up by throwing a number of trial pitches before playing.
the relief pitchers on a baseball team. Contrasted with starters.
the area beyond the outfield fence where relief pitchers wait and warm up.
a large cell where prisoners (people awaiting trial or sentence or refugees or illegal immigrants) are confined together temporarily
Area adjacent to the Clerk of Course in which swimmers are assembled and assigned to their heat and lane.
Keywords:  singular, noun
a singular noun