Compounds in which one or both oxygens of a carboxy group have been replaced by divalent
sulfur
RC(=O)SH or
RC(=S)OH monothiocarboxylic acids,
RC(=S)SH dithiocarboxylic acids.
Source:
PAC, 1995, 67, 1307
(Glossary of class names of organic compounds and reactivity intermediates based on
structure (IUPAC Recommendations 1995))
on page 1372