n pl but sing or pl in constr :  an allergic disorder marked by raised edematous patches of skin or mucous membrane and usu. by intense itching and caused by contact with a specific precipitating factor (as a food, drug, or inhalant) either externally or internally - called also urticaria  .
 
 
 
Similar sounding terms:  heaves 
 
Published under license with Merriam-Webster, Incorporated.  © 1997-2024.