c. 1600, "conversation, dialogue" (a sense now obsolete), from Latin colloquium "conference, conversation," literally "a speaking together," from com- "together" (see com-) + -loquium "speaking," from loqui "to speak" (from PIE root *tolkw- "to speak"). Also as a legal term; meaning "a meeting for discussion, assembly, conference, seminar" is attested by 1844.
colloidal
colloquia
colloquial
colloquialism
colloquialize
colloquium
colloquy
collude
collusion
collusive
collywobbles