1. the incrustation that forms over a sore or wound during healing.
2. Veterinary Pathology . a mangy disease in animals, especially sheep; scabies.
3. Plant Pathology .
a. a disease of plants characterized by crust-like lesions on the affected parts and caused by a fungus or bacterium.
b. one of these crust-like lesions.
4. a worker who refuses to join a labour union or to participate in a union strike, who takes a striking worker's place on the job, or the like.
5. a despicable person
6. Metallurgy .
a. a projection or roughness on an ingot or casting from a defective mould.
b. a surface defect on an iron or steel piece resulting from the rolling in of scale.
7. Carpentry . a short, flat piece of wood used for various purposes, as binding two timbers butted together or strengthening a timber at a weak spot.
- verb (used without object)
8 to become covered with a scab
9. (of a road surface) to become loose so that potholes develop