accession
UK: əkˈseʃ(ə)n | US: əkˈseʃ(ə)n
n. the act of attaining a position or rank (e.g., a throne)
n. the process of joining a group or agreement (e.g., treaty accession)
n. a new item added to a collection (e.g., library accessions)
Derived from Latin accessio ("approach, increase"), combining ac- (variant of ad-, meaning "to") + cess- (from cedere, "to go, yield"). Originally described the act of approaching or attaining something (e.g., power). Later extended to legal/collective contexts (e.g., treaty or museum additions). The morphemes reflect motion (cess) directed toward a goal (ac-), formalized into a noun (-ion).
The prince's accession to the throne was celebrated nationwide.
The country completed its accession to the EU in 2004.
The museum recorded 50 new accessions this year.
Treaty accession requires unanimous approval.
Her accession as CEO marked a shift in company strategy.