blackleg
US /ˈblæk.leɡ/
UK /ˈblæk.leɡ/

1.
a person who continues to work when fellow workers are on strike; a scab
:
•
The striking workers jeered at the blackleg crossing the picket line.
•
No one wants to be seen as a blackleg by their colleagues.
2.
a disease of cattle and sheep, especially young stock, caused by a bacterium (Clostridium chauvoei) and characterized by lameness and swelling of the muscles
:
•
The farmer quickly isolated the calf showing symptoms of blackleg.
•
Vaccination is crucial for preventing blackleg in livestock.