I. ˈ ̷ ̷ˌ ̷ ̷ noun
Etymology: black (I) + leg
1. : an enzootic usually fatal toxemia of young cattle and less commonly of sheep, goats, and swine characterized by high fever and crackling discolored swellings under the skin and caused by toxins produced by an anaerobic soil bacterium ( Clostridium feseri syn. C. chauvoei ) usually entering the tissues through minor wounds or abrasions — called also black quarter, symptomatic anthrax ; compare malignant edema
2. : a professional gambler : sharper , swindler
3. chiefly Britain : a worker hostile to trade unionism or acting in opposition to union policies : strikebreaker , scab
4.
a. : a destructive disease of cabbage and other plants especially of the family Cruciferae caused by certain fungi (as Phoma lingam ) and characterized by lesions in the stem near the soil surface that become sunken and dark and may girdle the stem
b. : a disease of potato plants caused by a bacterium ( Erwinia atroseptica ) that rots the bases of the stems with subsequent yellowing, wilting, and sometimes rotting of the tubers
II. verb
( blacklegged ; blacklegged ; blacklegging ; blacklegs )
chiefly Britain
transitive verb
: to act as a blackleg (sense 3) against
intransitive verb
: to act as a blackleg (sense 3)