adj. Of or pertaining to sulphur. (Chem.) (a) Derived from, or containing, sulphur; specifically, designating those compounds in which the element has a lower valence as contrasted with the sulphuric compounds. (b) Having the characteristic odor of sulphur dioxide, or of hydrogen sulphide, or of other sulphur compounds.
- Sulphurous acid. (a) Sulphur dioxide. See under Sulphur. (b) An acid, H2SO3, not known in the free state except as a solution of sulphur dioxide in water, but forming a well- known series of salts.
- Sulphurous anhydride (Chem.), sulphur dioxide. See under Sulphur.