SPARE

A hanger-on; a useless person who attaches herself to a group but is not so obnoxious that the others will actively try to drive her off. In any sufficiently large group of people, one person will be the spare. To find out who the spare is, ask the question, If we were being chased by Zombies, who would we shoot in the leg so the Zombies would stop to eat him, so that the rest of us could escape? Example: That's just Craig. Ignore him, he's our spare.