metonymy UK /mɪˈtɒnəmi/US /mɪˈtɑnəmi/ noun2 •A metonym. •(rhetoric) The use of a single characteristic or part of an object, concept or phenomenon to identify the entire object, concept, phenomenon or a related object.Metonymy does new names impose, And things for things by near relation shews. — 1835 formsmetonymies