dialogo

The seam is real, but it is Greek, not Esperanto. Dialogo was built once, in Greek, out of dia- (across, through) and logos (word, speech), and it entered Esperanto welded shut. You cannot cut it here. That matters because Esperanto happens to own both halves as other words entirely: dia is the adjective from dio and means divine, and logo looks like a noun off logi, to lure. A dialogue is not divine enticement. Read international roots whole, as the false friends article keeps insisting.

The logos shelf. Once log- is filed under word you get a run of them free: logogramo at rank 2672 is a word-sign, monologo a speech by one, prologo a fore-speech, epilogo an after-speech, and the whole -logio family (biologio, psikologio) is the study-of ending from the same source. Logiko too.

Two, or two sides? English speakers sometimes think a dialogue must have exactly two participants, on the strength of a di- they have imagined. It is dia-, across, and the count is not fixed: three characters on a stage are still in dialogue. The word for a speech by one person alone is monologo, and that prefix really does mean one.

Nearby. Interparoli is the plain verb, to talk with one another, and its noun interparolo is the everyday Esperanto word where English would say conversation. Konversacio is the borrowed alternative. Dialogo leans literary and diplomatic: a play has dialogue, and so do two governments that have stopped shouting.