A facial expression expressing one's criticism, disapproval, animosity, or scorn of varying levels of intensity towards another person. Defined by one person looking at the other out of the corner of their eye(s) with a scowl, as their head is turned in a different direction. Often an invitation for a fight or confrontation of some sort. Synonymous expression: "cuttin' your eyes" (at someone). Popular expression (and common occurrence) among urban American populations.

I couldn’t care less (but one must keep up appearances, right?)

Looking at somebody through your peripheral vision with disapproval

To give someone a knowing look. Usually when shocked or surprised by something.

When a girl that is taken or not taken is looking at you and you can see them out of the coner of your eye.

Description. When a member of the opposite sex looks from the corner of their at you in a obvious but discrete (obviously-discretely) way whilst in the company of their partner.