Interlocutory can mean "conversational," like the awkward dialogue that two strangers might have about the weather while riding in an elevator.
The Latin root of interlocutory is interloqui, "speak between." These days, this adjective is most often used in a legal context, to mean "temporary" or "non-final." An interlocutory decree, for example, is a judge's decision that doesn't settle the whole matter, but needs further court action to be complete. This definition comes from the "speak between" root of interlocutory, a reference to the period between legal actions, or discussion that happens in the middle of a lawsuit.