proparoxytone UK /pɹəʊpəˈɹɒksɪtəʊn/US /pɹoʊpəˈɹɑksɪtoʊn/adjective 1noun 1forms 1 adjective1 •Having the stress or accent on the antepenultimate syllable. noun1 •A proparoxytone word. formsproparoxytones