expiration
/ˌekspɪˈreɪʃən/noun
mass noun
1
- the ending of the fixed period for which a contract is valid期满; （合同的）有效期终止：
the expiration of the lease.
租约有效期的终止。
1.1
- the end of a period of time（一段时间的）结束, 终止：
the expiration of three years.
三年时间的结束。
2
- technical exhalation of breath〈技〉呼气, 吐气。
词源
late Middle English (denoting a vapour or exhalation)： from Latin exspiratio（n-）, from the verb exspirare （see EXPIRE）.