BLACKLEG
scab, strikebreaker, blackleg, rat
(noun) someone who works (or provides workers) during a strike
fink, scab, rat, blackleg
(verb) take the place of work of someone on strike
Source: WordNet® 3.1
Etymology
Noun
blackleg (countable and uncountable, plural blacklegs)
(countable) A person who takes the place of striking workers; a scab.
Synonyms: scalie, strikebreaker
(countable) A person who cheats in a game; a cheater.
(countable, colloquial) A notorious gambler.
(uncountable, agriculture, veterinary medicine) A fatal cattle disease caused by the soil-borne bacterium Clostridium chauvoei; symptomatic anthrax.
Verb
blackleg (third-person singular simple present blacklegs, present participle blacklegging, simple past and past participle blacklegged)
To continue working whilst fellow workers strike.
Source: Wiktionary
Black"leg`, n.
1. A notorious gambler. [Colloq.]
2. A disease among calves and sheep, characterized by a settling of
gelatinous matter in the legs, and sometimes in the neck. [Eng.]
Source: Webster’s Unabridged Dictionary 1913 Edition