four-oh-four
adjective [ after verb ] humorous disapproving (also 404) uk/ˌfɔː.rəʊˈfɔː/ us/ˌfɔːr.oʊˈfɔːr/
404（不知如何使用电子邮件和电脑的）傻瓜，菜鸟
used to describe someone stupid who does not know how to use email and computers
Don't bother asking him. He's 404, man. 别费事问他了，他是个电脑盲，老兄。