Compounds having an unbranched chain of sulfur atoms (S2 or higher) terminating in H: HSnH. Some chemists exclude disulfane, HS2H, from the class polysulfanes.
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]