frenulum of lip

We happily hoist our egg nog in the air, embrace each other, and raise our out-of-tune voices in song.

He paled a little, and sucked his lip, his eyes wandering to the girl, who stood in stolid inapprehension of what was being said.

The eyebrows were low and thick, the upper lip was sensitive, quivering sometimes as she talked, but the lower was firm and full.

You never know when you are going to stumble upon a jewel in the most out-of-the-way corner.

Ze under lip rather retires, and this adds to the receding effect of the chin, you see.

But Lessard's a overbearin' son-of-a-gun all round, and he's always breakin' out in a new place.