ex·pi·ra·tion 
/ˌɛkspəˈreɪʃən/ noun
/ˌɛkspəˈreɪʃən/ noun [noncount] 1 : the fact of coming to an end or no longer being valid after a period of time : the fact of expiring
▪ the patent's expiration ▪ one month after the expiration of the contract 2 medical : the act of breathing out
▪ inhalation and expiration [=exhalation]
▪ the patent's expiration ▪ one month after the expiration of the contract
▪ inhalation and expiration [=exhalation]
