A strikebreaker (sometimes pejoratively called a scab, blackleg, bootlicker, blackguard or knobstick) is a person who works despite a strike. Strikebreakers are usually individuals who were not employed by the company before the dispute but hired after or during the strike to keep the organization running. Strikebreakers may also refer to workers (union members or not) who cross picket lines to work.
The use of strikebreakers is a worldwide phenomenon; many countries have passed laws outlawing their use to give more power to unionized workers.