The Collaborative International Dictionary of English v.0.48:
Spar \Spar\, v. i. [imp. & p. p. Sparred; p. pr. & vb. n.
Sparring.] [Of uncertain origin; cf. OF. esparer to kick,
F. ['e]parer, or Icel. sperra to stretch out the legs, to
1. To strike with the feet or spurs, as cocks do.
2. To use the fists and arms scientifically in attack or
defense; to contend or combat with the fists, as for
exercise or amusement; to box.
Made believe to spar at Paul with great science.
3. To contest in words; to wrangle. [Colloq.]