Compounds R–[S]n–R , with a chain of sulfur atoms (\(n\geq 2\)) and R ≠ H. Some chemists exclude disulfides, RS2R , from the class polysulfides.
Source: PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1360 [Terms] [Paper]