ulterior: [17] Ulterior goes back to an unrecorded Latin *ulter ‘distant’ (a relative of ultrā ‘beyond’, source of the English prefix ultra-). Its comparative form was ulterior, which meant literally ‘more distant’. Its superlative form was ultimus, which lies behind English ultimate [17] and ultimatum [18] (etymologically the ‘farthest’ or last point). => ultimate, ultimatum[ulterior etymology, ulterior origin, 英语词源]