Simple past tense and past participle of sync.(verb)
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Use "synced" in a sentence
"Elsewhere, the video was innocuous - Mr. Fain practicing a phrase synced with the live account and then making tea, wandering around his apartment or taking a taxi."
"Ok, the fountain synced to the Civ 4 theme is pretty much awesome."
"You will note that there is a significant cross-circuit hum, and that the audio is de-synced from the video."