Scab (skab), n. [OE. scab, scabbe, shabbe; cf. AS. scæb, sceabb, scebb, Dan. & Sw. skab, and also L. scabies, fr. scabere to scratch, akin to E. shave. See Shave, and cf. Shab, Shabby.]
1.
An incrustation over a sore, wound, vesicle, or pustule, formed by the drying up of the discharge from the diseased part.
2.
The itch in man; also, the scurvy. [Colloq. or Obs.]
3.
The mange, esp. when it appears on sheep. Chaucer.
4.
A disease of potatoes producing pits in their surface, caused by a minute fungus (Tiburcinia Scabies).
5. (Founding)
A slight irregular protuberance which defaces the surface of a casting, caused by the breaking away of a part of the mold.
6.
A mean, dirty, paltry fellow. [Low] Shak.
7.
A nickname for a workman who engages for lower wages than are fixed by the trades unions; also, for one who takes the place of a workman on a strike. [Cant]
© Webster 1913
Scab, v. i. [imp. & p. p. Scabbed (?); p. pr. & vb. n. Scabbing.]
To become covered with a scab; as, the wound scabbed over.
© Webster 1913
Scab, n. (Bot.)
Any one of various more or less destructive fungus diseases attacking cultivated plants, and usually forming dark-colored crustlike spots.
© Webster 1913