blackleg

Etymology

From black + leg.

noun

1. (uncountable, agriculture, veterinary medicine) A fatal cattle disease caused by the soil-borne bacterium Clostridium chauvoei; symptomatic anthrax.
2. (countable) A person who cheats in a game; a cheater, especially a dishonest bookmaker.
   [H]ere, then, was a community of good taste and kind feeling, no sharpers, no black-legs, no wolves in sheep's clothing. 31 December 1836, Laurie Todd, “Letter from Laurie Todd: Christmas and New-Year’s-Day”, in New-York Mirror, a Weekly Journal, Devoted to Literature and the Fine Arts, volume XIV, number 27, New York, N.Y.: Scott & Co., printers, →OCLC, page 211, column 1
   They have no regard for respectability like yours — nothing between a baron and a blackleg. 1852?, The Sporting Magazine (page 185)
3. (countable) A person who takes the place of striking workers; a scab.
   It's in the evening after dark when the blackleg miner creeps to work. With his moleskin pants and his dirty shirt, there goes the blackleg miner. 1970-06, traditional (lyrics and music), “The Blackleg Miner” (track 4), in Hark! The Village Wait, performed by Steeleye Span

verb

1. To continue working whilst fellow workers strike.
   Why was I there, munitioning, blacklegging, slaving as though my bread depended on it? 1939, Philip George Chadwick, The Death Guard, page 154