sulphanilamide /sʌlfəˈnɪləmaɪd/ noun2 •Any of a class of amino substituted aromatic sulfonamides that are used as antifungal antibiotics; but especially the parent compound 4-aminobenzenesulfonamide •The amide of sulphanilic acid, used to treat streptococcal infections; the parent compound of the sulphonamides. formssulphanilamides