noun A dry, rough protective crust that forms over a cut or wound during healing. (As this mesh dries, it hardens and forms a scab to protect the wound as it heals.) Mange or a similar skin disease in animals. (The state was also called in to deal with stock disease, especially scab - a major constraint on wool production.) A person or thing regarded with dislike and disgust.
verb Become encrusted or covered with a scab or scabs. (I had a cut on my arm that had scabbed over) Act or work as a scab.