scab
/skæb; skæb/ n
1 [C, U] dry crust formed over a wound or sore as it heals 痂.
2 [U] disease of skin or plants causing scab-like roughness 疥癣: sheep-scab 羊疥癣.
3 [C] (infml derog 口, 贬) worker who refuses to join a strike or a trade union, or who takes the place of a striker; blackleg 拒绝参加罢工的工人; 拒不参加工会的工人; 顶替罢工者工作的人; 工贼.