If you do meet Horatio and Marcellus,
The rivals of my watch, bid them make haste. Shak.

* "Rivals, in the primary sense of the word, are those who dwell on the banks of the same stream. But since, as all experience shows, there is no such fruitful source of coutention as a water right, it would continually happen that these occupants of the opposite banks would be at strife with one another in regard of the periods during which they severally had a right to the use of the stream . . . And thus 'rivals' . . . came to be used of any who were on any grounds in more or less unfriendly competition with one another." Trench.

Syn. -- Competitor; emulator; antagonist.

The strenuous conflicts and alternate victories of two rival confederacies of statesmen. Macaulay.

To rival thunder in its rapid course. Dryden.