Lip Sing Share definition Flag 1. What the total dumb-asses on YouTube say when they actually mean "lip SYNC". OMG SHE IS TOTALLY LIP SINGING!!!!!!1111" "No, she's lip SYNCing." "NO THAT DOESN'T MAKE SENSE! Lip Sing by Your dad's mother. July 26, 2010 0 0 Get merch Get the Lip Sing mug. Buy Now — $32.95 See more merch