1. Of or pertaining to a sulphur compoud in which sulphur has a valence of 4. Contrasted to sulphuric compounds in which sulphur has a valence of +6, or sulfides (-2).

2. <chemistry> Derived from, or containing, sulphur; specifically, designating those compounds in which the element has a lower valence as contrasted with the sulphuric compounds.

Having the characteristic odour of sulphur dioxide, or of hydrogen sulphide, or of other sulphur compounds.

<chemistry> Sulphurous anhydride, sulphur dioxide.

Origin: L. Sulphurosus, sulphurosus: cf. F. sulphureux.

American spelling: sulfurous

(01 Mar 1998)