The action or process of adding a soundtrack to a video recording or replacing a soundtrack without affecting the existing video track; a facility which enables this.
Origin
1970s. From audio + dubbing [noun²].
Definition of audio dubbing in US English:
audio dubbing
nounˌɔːdɪəʊ ˈdʌbɪŋ
The action or process of adding a soundtrack to a video recording or replacing a soundtrack without affecting the existing video track; a facility which enables this.