3rd Impostor

(slang, noun, Among Us):
A dig at a player that is acting suspicious, but is otherwise definitely not The Impostor.

This “Crewmate” player may be failing to complete their tasks, accusing the wrong people, or not voting in line with the majority. Although they aren't necessarily killing anyone or trying to lose, their chaotic playstyle makes them seem like a mini-Impostor, or if you will, a “third Impostor.”