See more synonyms for scab on
  1. the incrustation that forms over a sore or wound during healing.
  2. Veterinary Pathology. a mangy disease in animals, especially sheep; scabies.Compare itch(def 10).
  3. Plant Pathology.
    1. a disease of plants characterized by crustlike lesions on the affected parts and caused by a fungus or bacterium.
    2. one of these crustlike lesions.
  4. a worker who refuses to join a labor union or to participate in a union strike, who takes a striking worker's place on the job, or the like.
  5. Slang. a rascal or scoundrel.
  6. Metallurgy.
    1. a projection or roughness on an ingot or casting from a defective mold.
    2. 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), scabbed, scab·bing.
  1. to become covered with a scab.
  2. to act or work as a scab.

Origin of scab

1200–50; 1800–10 for def 4; Middle English < Old Norse skabb scab, itch; cf. shabby, shave
Related formsscab·like, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for scab

Historical Examples of scab

  • Threats against "scabs" were shouted out, the word "scab" arose on every side.

    The Harbor

    Ernest Poole

  • In those days they used a scab from the arm of someone who had been vaccinated.

  • When the scab was all off, the nose was found to be quite uninjured.

  • This scab is caused by a fungous growth on the surface of the potato.

    Agriculture for Beginners

    Charles William Burkett

  • With the same (or Bordeaux for scab) just after the blossoms fall.

    Apple Growing

    M. C. Burritt

British Dictionary definitions for scab


  1. the dried crusty surface of a healing skin wound or sore
  2. a contagious disease of sheep, a form of mange, caused by a mite (Psoroptes communis)
  3. a fungal disease of plants characterized by crusty spots on the fruits, leaves, etc
  4. derogatory
    1. Also called: blacklega person who refuses to support a trade union's actions, esp one who replaces a worker who is on strike
    2. (as modifier)scab labour
  5. a despicable person
verb scabs, scabbing or scabbed (intr)
  1. to become covered with a scab
  2. (of a road surface) to become loose so that potholes develop
  3. to replace a striking worker
Derived Formsscablike, adjective

Word Origin for scab

Old English sceabb; related to Old Norse skabb, Latin scabiēs, Middle Low German schabbe scoundrel, German schäbig shabby
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for scab

mid-13c., "skin disease," developed from Old English sceabb "scab, itch" (related to scafan "to shave, scrape, scratch") and from Old Norse skabb "scab, itch," both from Proto-Germanic *skab- "scratch, shave," from PIE *(s)kep- "to cut, scrape, hack" (see scabies). Sense reinforced by cognate Latin scabies "scab, itch, mange" (from scabere "to scratch").

Meaning "crust which forms over a wound or sore" is first attested c.1400. Meaning "strikebreaker" first recorded 1806, from earlier sense of "person who refuses to join a trade union" (1777), probably from meaning "despicable person" (1580s), possibly borrowed in this sense from Middle Dutch.

Online Etymology Dictionary, © 2010 Douglas Harper

scab in Medicine


  1. A crust formed from and covering a healing wound.
  2. Scabies or mange in domestic animals or livestock, especially sheep.
  1. To become covered with scabs or a scab.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

scab in Science


  1. A crust that forms over a healing wound, consisting of dried blood, plasma, and other secretions.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

scab in Culture


Informally, a worker who stays on the job while others go on strike. Also, a worker brought in to keep a plant operating when its work force is on strike. (See strikebreaker.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.