dapsone UK /ˈdap.səʊn/US /ˈdæpˌsoʊn/ noun1 •A bacteriostatic antimicrobial agent 4-[(4-aminobenzene)sulfonyl]aniline (C₁₂H₁₂N₂O₂S) used in the treatment of leprosy and a chronic form of dermatitis. formsdapsones