The phrase "dub in" means to add or replace sound, usually dialogue, in a film or TV show. There are several synonyms for this term, including "voice-over," "re-record," "ADR" (which stands for automated dialogue replacement), and "looping." Voice-over is a technique where a character's spoken words are recorded separately and then added to the scene in post-production. Re-recording involves replacing the original audio with a new recording. ADR typically involves recording a character's dialogue in a studio and then synchronizing it with the actor's lip movements onscreen. Looping refers to the process of recording a small section of dialogue repeatedly until it matches up perfectly with the visual action onscreen.