If you have ID or an ID, you are carrying a document such as an identity card or driver's licence which proves that you are a particular person.
例句
I had no ID on me so I couldn't prove I was the owner of the car...我身上没带身份证件,也就无法证实我就是车主。Peter took out his wallet and showed his ID to the man...彼得掏出钱包向那人出示他的身份证件。
行业词典
计算机: = Integrated Data Store (Honeywell),综合数据存储器(霍尼韦尔公司); = Integrated Display System (HP), 综合显示系统(HP公司); = Interactive Design System (Gerber), 交互设计系统(Gerber公司); = International Data Sciences Inc., 国际数据科学公司;