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.

-Urban Dictionary