assertion (n.)youdaoicibaDictYouDict[assertion 词源字典]
early 15c., assercioun, from Middle French assertion (14c.) or directly from Late Latin assertionem (nominative assertio), noun of action from past participle stem of Latin asserere "claim rights over something, state, maintain, affirm," from ad- "to" (see ad-) + serere "join" (see series). By "joining oneself" to a particular view, one "claimed" or "maintained" it.[assertion etymology, assertion origin, 英语词源]