Strikebreakers
A strikebreaker is someone who continues to work during strike action by trade unionists or temporary and permanent replacement workers hired to take the place of those on strike. Strikebreakers are commonly given derogatory terms like scab and blackleg. The act of working during a strike – whether by strikebreakers, management personnel, non-unionized employees or members of other unions not on strike – is known as crossing the picket line, regardless of whether it involves actually physically crossing a line of picketing strikers. Crossing a picket line can result in passive and/or active retaliation against that working person.
Irwin, Jones, McGovern (2008) believe that the term 'scab' is part of a larger metaphor involving strikes. They argue that the picket line is symbolic of a wound and those who break its borders to return to work are the scabs who bond that wound. Others have argued that the word is not a part of a larger metaphor but, rather, originates from the old-fashioned English insult, "scab." The OED gives the etymology of 'scab' in this sense as a term of abuse or depreciation derived from the MDu. schabbe, applied to women with the senses ‘slut’ and ‘scold’ and 'scurvy'.
"Blackleg" is an older word and is found in the late-nineteenth/early-twentieth century folk song from Northumberland, Blackleg Miner. The term does not necessarily owe its origins to this tune of unknown origin. The song is, however, notable for its lyrics that encourage violent acts against strikebreakers.
Read more about this topic: Strike Action