1) Conversation 2) Dialog 3) Dialogue 1) Conversation for two 2) Dialog 3) Dialogue 4) Screenplay for two actors 5) Talk 6) Talking 
a play for two actors. Example: 'Pepper and Sand,' a duologue by Emlyn Williams, 1m1f.
[n] - a part of the script in which the speaking roles are limited to two actors
A part of a play with speaking roles for only two Actors
noun a part of the script in which the speaking roles are limited to two actors
Scripted dialogue for two persons, usually actors. Duologues, monologues and discourses were also used in certain periods for non-fiction writing, in order to express ideas in a more entertaining or more comprehensible form (for example, in The Compleat Angler (1653) by Isaak Walton, and in Plato's written dialogues)
a conversation between two persons; dialogue. · a dramatic performance or piece in the form of a dialogue limited to two speakers.