Noun
(inorganic chemistry, in combination) Two atoms of sulfur in a compound.
A diatomic molecule of sulfur, S2
Source: en.wiktionary.orgSulfur tetrafluoride is rarely used organic reagent that and is highly toxic. citation Sulfur dichloride and disulfur dichloride are important industrial chemicals. Source: Internet
Sulfur vapor is mostly disulfur (S 2 ). Source: Internet