When in a theater with shared armrests, the act of carefully adjusting one's posture so that your arm touches the arm of the person next to you, but not so much that they move their arm away.
> Jenna was pretty sure Mark still believed in cooties, so she got all giddy during their Ice Age 3 date when she "won" a game of elbow tag.
> Land of the Lost was so painful, I had to amuse myself by playing elbow tag with the stranger on my left.
