The Collaborative International Dictionary
Collocutor
Collocutor \Col"lo*cu`tor\, n. [L. collocutor]
One of the speakers in a dialogue.
--Derham.
Wiktionary
collocutor
n. Any of the people engaged in a conversation
Usage examples of "collocutor".
Observation of his collocutor led him shortly to alter his tone a little.