accession (n.)youdaoicibaDictYouDict[accession 词源字典]
"act of coming to a position," especially of a throne, 1640s, from Latin accessionem (nominative accessio) "a going to, joining, increase," noun of action from past participle stem of accedere "approach, enter upon" (see accede).[accession etymology, accession origin, 英语词源]