scab Definition

scab
noun

1. A crust of dried blood formed over a healing wound.
2. A contagious skin disease of sheep caused especially by mites, characterized by pustules or scales.
3. A plant disease caused by a fungus, producing crusty spots.
4. derog, slang
A worker who defies a union's instruction to strike. Also called blackleg.
5. derog
A scoundrel; a contemptible person.

verb, intr scabbed, scabbing

1. To become covered by a scab.

Form: scab over (also)
2. slang
To work or behave as a scab.

Etymology: Anglo-Saxon sceabb.