Undersecretary rhymes with:
budgetary, depositary, sanitary, unitary, budgetary, cemetery, cometary, commentary, depositary, dietary, dignitary, dysentery, fragmentary, hereditary, interplanetary, involuntary, military, momentary, monastery, monetary, nonmilitary, paramilitary, pituitary, planetary, proprietary, salutary, sanitary, secretary, sedentary, solitary, tributary, unitary, unsanitary