[scab] n [ME, of Scand origin; akin to OSw skabbr scab; akin to OE sceabb scab, L scabere to scratch--more at shave] (13c) 1: scabies of domestic animals
2: a crust of hardened blood and serum over a wound 3 a: a contemptible person b (1): a worker who refuses to join a labor union (2): a union member who refuses to strike or returns to work before a strike has ended (3): a worker who accepts employment or replaces a union worker during a strike (4): one who works for less than union wages or on nonunion terms
4: any of various bacterial or fungus diseases of plants characterized by crustaceous spots; also: one of the spots
[2]scab vi scabbed ; scab.bing (1683) 1: to become covered with a scab
2: to act as a scab