Definition of lip-sync in English:

lip-sync

(also lip-synch)

verb

[NO OBJECT]
  • (of an actor or singer) move the lips silently in synchronization with a recorded soundtrack.

    [with object] ‘several singers were alleged to have lip-synched their songs’
    • ‘I say pantomime because it isn't even lip-synching.’
    • ‘She lip-synched, but the track was pre-recorded, and she was singing!’
    • ‘The sound may very well be lip-synched - and if it isn't, the audio is so poorly recorded as to make lip-synching preferable.’
    • ‘The best thing about Bollywood movies is that its actors are all really good at lip-synching.’
    • ‘She wanted to sing; she even filmed several scenes lip-synching to her own temp tracks.’
    • ‘In high school he put on a most peculiar theatrical production: a musical version of David Lynch's Blue Velvet with actors lip-synching to the songs of Marianne Faithful.’
    • ‘For most TV and live performances, this studio recording will simply be played through the sound system, and the singer will convincingly lip-synch the performance.’
    • ‘Instead, his actors lip-synch to the prerecorded music.’
    • ‘In fact, many of the clips feature the artists lip-synching to their music on teen dance programs.’
    • ‘That doesn't mean we don't have great performances where actors are lip-synching.’
    • ‘I know the country is bristling with musical talent and an invigorated, cringe-less culture has emerged where once we lip-synched to an imported soundtrack.’
    • ‘I found the English track excellent, with good voice acting and no problem with lip-synching.’
    • ‘It's beautifully picturised, and sung by the actor who is supposed to be singing it - which is rare in Indian films, where the actors generally lip-synch songs sung by others.’
    • ‘The movies are musicals, but the actors don't sing; they lip-synch to songs previously recorded by playback singers.’
    • ‘Very few Indian actors can sing and dance, everything is lip-synced with backup singers and there is a choreographer to take care of all the dance routines.’
    • ‘The actors lip-synch with the music in the background.’
    • ‘Their Siegfried injured his leg, so his understudy lip-synced the role while the hurt tenor sang from a chair.’
    • ‘Shot in and around some castle or other in 1971, this is a film, not a stage production, which means the singers lip-synch to their pre-recorded voices.’
    • ‘The Internet is buzzing with amateur videos, the kind that feature kids lip-synching or imitating Jedi knights.’
    • ‘So a live orchestra was playing a sampled part while the singer lip-synced to prerecorded vocals.’

Pronunciation:

lip-sync

/ˈlip ˌsiNGk/