(medicine) An infectious disease caused by the bacterium Mycobacterium leprae, gradually producing nerve damage and patches of skin necrosis and historically handled by permanently quarantining its sufferers.

(medicine, now usually proscribed) Similar contagious skin diseases causing light patches of scaly skin, particularly psoriasis, syphilis, vitiligo, scabies, and (biblical) the various diseases considered "tzaraath" in the Old Testament.

(figurative) Anything considered similarly permanent, harmful, and communicable, particularly when such a thing should be handled by avoidance or isolation of its victims.

A contagious disease that affects animals, particularly rodents and cats, caused by mycobacterium lepraemurium, and is also a synonym for mange and glanders in horses.

(obsolete, rare) Synonym of leprosarium: a place for the housing of lepers in isolation from the rest of society.