interlocution comes from Latin interlocutio ('a speaking between'), from interloqui ('to speak between, interrupt'), from inter- ('between') + loqui ('to speak'). Morphologically, the prefixed shape matters: the initial element belongs to the recorded formation and helps explain the modern form's surface analysis. In present English, the noun sense is "dialogue or conversation; an interchange of speech", so the historical development ends in a clearly identifiable modern dictionary use. The same base also appears in related forms such as interlocutor, interlocutory, locution, and elocution. Its semantic neighborhood includes dialogue, conversation, colloquy, and discourse, which helps locate the modern sense without adding a separate etymological claim. The named historical forms include Latin interlocutio and Latin loqui.