9 Grammatical Pitfalls
early 13c., "literary work consisting of a conversation between two or more persons," from Old French dialoge, from Latin dialogus, from Greek dialogos "conversation, dialogue," related to dialogesthai "converse," from dia- "across" (see dia-) + legein "speak" (see lecture (n.)).
Sense broadened to "a conversation" c.1400. Mistaken belief that it can only mean "conversation between two persons" is from confusion of dia- and di- (1). A word for "conversation between two persons" is the hybrid duologue (1864).
1. A commercial bibliographic database and retrieval service from DIALOG Information Services.
2. Interactive mathematics using a graphics tablet by Illinois Inst Tech, 1966.
["DIALOG: A Conversational Programming System with a Graphical Orientation", S.H. Cameron et al, CACM 10:349-357 (1967). Sammet 1969, p.255-258].