From WordNet (r) 3.0 (2006) :
spar
n 1: any of various nonmetallic minerals (calcite or feldspar)
that are light in color and transparent or translucent and
cleavable
2: a stout rounded pole of wood or metal used to support rigging
3: making the motions of attack and defense with the fists and
arms; a part of training for a boxer [syn: spar,
sparring]
v 1: furnish with spars
2: fight with spurs; "the gamecocks were sparring"
3: box lightly
4: fight verbally; "They were sparring all night"