In the context of organized labor, a scab is a derogatory term referring to a worker who declines to join a union, leaves the union, or accepts a job during a strike, thereby undermining the striking workers bargaining power. The term "scab" has been used since the late 1700s to refer to workers who refused to join a union or acted in a way that would undermine their fellow workers. The term "scab" is also used to refer to strikebreakers, who are individuals who work despite a strike. Union members say scabs "cross the picket line" when they do this because they undermine the striking workers bargaining power. The term "scab" is considered a pejorative term and is used to shame individuals who are perceived to be undermining the collective bargaining power of the union.