blackleg

noun

black·​leg ˈblak-ˌleg How to pronounce blackleg (audio)
-ˌlāg
Synonyms of blacklegnext
1
: a usually fatal toxemia especially of young cattle caused by a soil bacterium (Clostridium chauvoei)
2
: a cheating gambler : swindler
3
chiefly British : a worker hostile to trade unionism or acting in opposition to union policies : scab

Word History

First Known Use

circa 1722, in the meaning defined at sense 1

Time Traveler
The first known use of blackleg was circa 1722

Cite this Entry

“Blackleg.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/blackleg. Accessed 5 Jul. 2026.

Medical Definition

blackleg

noun
black·​leg ˈblak-ˌleg, -ˌlāg How to pronounce blackleg (audio)
: an enzootic usually fatal toxemia especially of young cattle caused by toxins produced by an anaerobic soil bacterium of the genus Clostridium (C. chauvoei synonym C. feseri)

called also black quarter, quarter evil, quarter ill, symptomatic anthrax

compare black disease, malignant edema

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