eth′yl sul′fide,[Chem.]a colorless, oily, slightly water-soluble liquid, C4H10S, having a garliclike odor: used chiefly as a solvent for certain salts and in organic synthesis. Also called eth•yl•thi•o•e•ther(eth′əl thī′ō ē′thər),USA pronunciationeth•yl•thi•o•eth•ane(eth′əl thī′ō eth′ān).USA pronunciation