Entry 1 sense Webster, 1913 Disulphate · Di·sul·phate · IPA /dɪˈsʌɫfeɪt/ 01 n. A salt of disulphuric or pyrosulphuric acid; a pyrosulphate. 1. A salt of disulphuric or pyrosulphuric acid; a pyrosulphate.(Chem.)