• Scab, a hard coating on the skin formed during the wound healing reconstruction phase
• Derogatory term for a strikebreaker
  Strikebreaker
  A strikebreaker is a person who works despite an ongoing strike. Strikebreakers are usually individuals who are not employed by the company prior to the trade union dispute, but rather hired prior to or during the strike to keep the organisation running...
  
  , a person who works despite strike action or against the will of other employees
  • Scab union, an organization of workers perceived as having a role in strike breaking
• Scab (Australasian/British slang), a person who obtains things for free, especially from verge
  Verge
  Verge and similar may refer to:*Road verge, a strip of grass or other vegetation beside a road*The Verge , a technology news network*Verge escapement, a clock escapement mechanism*Verge , area of space in David Weber's Honorverse...
  
   collections or giveaways from friends (a practice known as scabbing)
• SCAB, Acronym for the South Coast Air Basin
  South Coast Air Basin
  The South Coast Air Basin is one of several geopolitical areas designated by the state of California, U.S., for the purpose of air quality management. An air basin is associated with a ring or partial ring of mountains that in the absence of winds holds air and smog within the area...
  
   in California
  California
  California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
  
  , U.S.

Animal and plant diseases

• Apple scab
  Apple scab
  Apple scab is a disease to Malus trees, such as apple trees, caused by the ascomycete fungus Venturia inaequalis. The disease manifests as dull black or grey-brown lesions on the surface of tree leaves, buds or fruits. Lesions may also appear less frequently on the woody tissues of the tree. Fruits...
  
  , an apple tree (genus Malus) fungal disease caused by Venturia inaequalis
• Black scab, a potato fungal disease caused by Synchytrium endobioticum
• Fusarium head blight, a fungal disease of plants, e.g., grain crops (especially wheat and oats), golf course grass, caused by the several species of Fusarium
• Pear scab, a pear fungal disease caused by Venturia pirina or Fusicladium pyrorum
• Poinsettia scab, a spot anthracnose disease caused by Sphaceloma poinsettiae
  Sphaceloma poinsettiae
  Sphaceloma poinsettiae is a plant pathogen. It causes poinsettia scab, which is a spot anthracnose disease.- External links :* *...
  
  
• Powdery scab
  Powdery scab
  Powdery scab, is a disease that happens to tubers. It is caused by the cercozoan Spongospora subterranea, is widespread in potato growing countries. Symptoms of powdery scab include small lesions in the early stages of the disease, progressing to raised pustules containing a powdery mass. Powdery...
  
  , a tubers disease caused by the protozoa Spongospora subterranea
• Sheep scab, a skin disease of sheep caused by the mite Psoroptes ovis
• U.S. Wheat and Barley Scab Initiative
  U.S. Wheat and Barley Scab Initiative
  The U.S. Wheat and Barley Scab Initiative was founded in 1998. The Initiative's goal is to develop as quickly as possible effective control measures that minimize the threat of Fusarium head blight , including the reduction of mycotoxins, to the producers, processors, and consumers of wheat and...
  
  , a joint government and academic program to develop control measures to minimize the threat of Fusarium head blight (scab)

Geology

• Scablands
  Channeled scablands
  The Channeled Scablands are a unique geological erosion feature in the U.S. state of Washington. They were created by the cataclysmic Missoula Floods that swept periodically across eastern Washington and down the Columbia River Plateau during the Pleistocene epoch. Geologist J Harlen Bretz coined...
  
  are a unique geological erosion feature in the U.S. state of Washington caused by cataclysmic floods .