corrival
A fellow rival; a competitor; a rival.
Without corrival all her dignities: But out upon this half-facd fellowship!
So he that doth redeem her thence might wearA companion.
archaic
The noble Westmoreland, and warlike Blunt; And many more corrivals and dear men Of estimation and command in arms.
The Prince of Wales, Lord John of Lancaster,
Where it comes from
From Middle French corrival, from Latin corrīvālis.
Adapted from the Wiktionary entry corrival (CC BY-SA 4.0).