[, ] ( ˌexpectation of ˈlife) the number of years that a person is likely to live预期寿命◆Pension fund managers have to cope with longer life expectancy and new pension regulations.退休金基金经理人需要面对更长的预期寿命和新的退休金条例。the length of time that sth is likely to exist or continue for预计存在(或持续)的期限◆the short life expectancy of dotcoms昙花一现的网络公司the length of time that an asset is likely to be used for资产的预期使用期限