GNU Collaborative International Dictionary of English

Found 2 definitions

1.       
   Scab , n. [OE. scab, scabbe, shabbe; cf. AS. scaeb, sceabb, scebb, Dan. & Sw. skab, and also L. scabies, fr. scabere to scratch, akin to E. shave. See Shave, and cf. Shab, Shabby.]
   An incrustation over a sore, wound, vesicle, or pustule, formed by the drying up of the discharge from the diseased part.
   1913 Webster
   The itch in man; also, the scurvy. [Colloq. or Obs.]
   1913 Webster
   The mange, esp. when it appears on sheep.
   Chaucer.
   
   1913 Webster
   A disease of potatoes producing pits in their surface, caused by a minute fungus (Tiburcinia Scabies).
   1913 Webster
   (Founding) A slight irregular protuberance which defaces the surface of a casting, caused by the breaking away of a part of the mold.
   1913 Webster
   A mean, dirty, paltry fellow. [Low]
   Shak.
   
   1913 Webster
   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]
   1913 Webster
   (Bot.) Any one of various more or less destructive fungus diseases attacking cultivated plants, and usually forming dark-colored crustlike spots.
   Webster 1913 Suppl.
         
       

2.       
   Scab, v. i. [imp. & p. p. Scabbed ; p. pr. & vb. n. Scabbing.]
   To become covered with a scab; as, the wound scabbed over.
   1913 Webster
   to take the place of a striking worker.
   PJC