scab

noun
1
a hard dry layer that forms over and covers a wound on the skin as it gets better
دلمه زخم, پوسته زخم, کبره
2
a worker who refuses to join a strike or takes the place of somebody on strike
اعتصاب‌شکن, کارگر اعتصاب‌شکن, کارگر غیر اعتصابی
synonym blackleg
3
a skin disease of animals
جرب, گال
4
a disease of plants, especially apples and potatoes, that causes a rough surface
کچلی گیاه, خارشک