Lewis Short
collŏcūtĭo | conl- (noun F) : (), , colloquor
* A (familiar or private) conversation, conference (very rare): hominum,Cic. Tusc. 1, 13, 30; id. Att. 12, 1, 2: venire cum aliquo in collocutionem,Auct. Her. 1, 15, 25.—In plur.: familiarissimae cum aliquo,Cic. Phil. 11, 2, 5: in sermonibus collocutionibusque aliquid videre,id. Fam. 1, 9, 4.
Charlton T. Lewis, Charles Short, A Latin Dictionary