A formal discussion between enemies or opponents is called a parley. A British drummer called for a parley between the British and American armies in 1781, and officers from both sides then discussed the terms of Britain's surrender.

Parley can also be used as a verb, meaning to discuss or negotiate, such as between enemies or opponents. If your siblings are fighting, you may need to encourage them to parley in another room in order to discuss their differences and hopefully settle the problem once and for all.

Definitions of parley

n a negotiation between enemies

Type of:
dialogue, negotiation, talks
a discussion intended to produce an agreement

v discuss, as between enemies

have a lengthy discussion, usually between people of different backgrounds
Type of:
confer with another in order to come to terms or reach an agreement