expiration of term of office
Formal term used in official, legal, or organizational contexts when a fixed term ends.
The mayor's term of office expires in March next year.
任期 refers to the term of office itself, while 任期満了 specifically means the expiration of that term.
満了 means expiration or completion of a period; it is often used in compounds like 任期満了 or 契約満了.
Compound of 任期 (term of office) and 満了 (expiration, completion).