'Blackleg' definitions:

Definition of 'blackleg'

(from WordNet)
noun
Someone who works (or provides workers) during a strike [syn: scab, strikebreaker, blackleg, rat]
verb
Take the place of work of someone on strike [syn: fink, scab, rat, blackleg]

Definition of 'Blackleg'

From: GCIDE
  • Blackleg \Black"leg`\, n.
  • 1. A notorious gambler. [Colloq.] [1913 Webster]
  • 2. A disease among calves and sheep, characterized by a settling of gelatinous matter in the legs, and sometimes in the neck. [Eng.] [1913 Webster]

Synonyms of 'blackleg'

From: Moby Thesaurus