laugh·lineor laugh line (lăf′līn′, läf′-)
1. A lasting wrinkle formed at the outer corner of the eye or along the side of the mouth, especially noticeable when one laughs or smiles.
2. A line of dialogue intended to cause laughter: "actors who are directed ... to cutely underline every nuance and laughline" (Laurie Winer).
a wrinkle near the outer corner of the eye, as if left from smiling or laughing