Source : Webster's Revised Unabridged Dictionary (1913)

Monomachia \Mon`o*ma"chi*a\, Monomachy \Mo*nom"a*chy\, n. [L.
   monomachia, Gr. ?, fr. ? fighting in single combat; ? single,
   alone + ? to fight.]
   A duel; single combat. ``The duello or monomachia.'' --Sir W.
   Scott.