olfactory UK /ɒlˈfak.tə.ɹi/US /ɑlˈfæk.təɹ.i/adjective 1noun 2forms 1 adjective1 •Concerning the sense of smell.Dogs possess a highly developed olfactory system.The disease can impair olfactory function. noun2 •[in the plural] The sense of smell. •Ellipsis of olfactory organ. formsolfactories