'Protosulphide' definitions:

Definition of 'Protosulphide'

From: GCIDE

Protosulphide \Pro`to*sul"phide\, n. [Proto- + sulphide.] (Chem.) That one of a series of sulphides of any element which has the lowest proportion of sulphur; a sulphide with but one atom of sulphur in the molecule. [1913 Webster]