Prelap

Prelap is a word mostly used in the screenwriting business, and is typically used within a screenplay. It simply means that the dialogue from the incoming scene precedes the cut, and you hear the beginning of the dialogue in the outgoing scene. As an example:

ADRIAN (O.S., PRELAP) Peter? Peter, where are you? EXT. THE WOODS -- DAY Adrian is out looking for Peter. We see him wander around in the small forest. ADRIAN Peter? Hello? Are you there?

As you can see in this example, Adrian's voice precedes the scene out in the woods. The 'O.S.' means 'Off Screen' and the 'PRELAP' indicates that Adrian's dialogue should be heard before we enter the next scene. Adrian, in this example, might not even be in the scene we are in, when the prelap occurs.

'Prelaps' can be of sound and dialogue, i.e. non-visuals, since a visual would indicate a direct cut to a new scene.