lip-sync

listen to the pronunciation of lip-sync
İngilizce - Türkçe
dudak senkronizasyon
İngilizce - İngilizce
To move lips in synchronization with sounds (generally recorded) so it appears they are the source of the sounds

There was a great scandal when it was discovered the singer had been only lip-syncing.

move the lips in synchronization (with recorded speech or song)
to move the lips in synchronization with recorded sound
the synchronization of audio and video signals such that there is no lack of simultaneity between them
lipsync
Alternative spelling of lip sync