facial muscle n.
Any of the numerous muscles supplied by the facial nerve and that attach to and move the skin. Also called muscle of facial expression.
Farrell returned the salute without so much as the twitch of a facial muscle.
"Hannibal," said the man, without the flicker of a facial muscle.
You were forced to admit that every gesture, every movement of a facial muscle, had a true purpose, a raison d'être.