What is "adverse parties"

Usage examples of "adverse parties".

There was, moreover, a circumstance that confirmed them in this resolution: for of the two adverse parties, that, which had stood by Sertorius in the late war, being conquered by Pompey, still trembled at his name and sway, though absent: the other which had remained firm in Pompey's interest, loved him for the favors which they had received: but Caesar's name was not known to the barbarians.

The adverse parties post themselves on the opposite sides of the stream, and at such distances that the battles often last a long while before any blood is shed.

Then Jim Kirk became aware of something else, a kind of subtle agitation in the air, quite aside from the expected tension of two traditionally adverse parties meeting for the first time.