adj.(法律上或官方)不承认的，无效的，无充分事实的，站不住脚的，不能识别的
n.病弱者，久病衰弱者
vt.(因伤病)令…退役

原形：invalid第三人称单数：invalids复数：invalids过去式：invalided过去分词：invalided现在分词：invaliding

A identity card that is out of date is invalid.
过期的身份证是无效的。
The invalid kid is confined to a wheel chair.
这个体弱多病的孩子能坐在轮椅里活动。
The invalid is very irritable, but we try to accommodate her.
那病人极易发怒我们尽量包容她。
.
The submission is invalid due to missing required information.
这份提交无效，因为缺少了必需的信息。
The password you entered is invalid; it must contain at least one number and one special character.
你输入的密码无效；它必须包含至少一个数字和一个特殊字符。
The credit card number provided is invalid – please check and try again.
提供的信用卡号码无效，请检查后重试。
Your registration was marked as invalid, please contact customer support for assistance.
你的注册被标记为无效，请联系客户服务寻求帮助。
The URL you clicked on is invalid; the webpage cannot be found.
你点击的链接无效；找不到该网页。
The software license key you entered is invalid – please enter a valid key.
你输入的软件许可证密钥无效，请输入有效的密钥。
The answer you submitted is incorrect; please provide an valid solution.
你提交的答案是错误的，请提供一个有效的解决方案。
This email address appears to be invalid; please verify and update your details.
这个电子邮件地址似乎无效，请核实并更新你的信息。
The form you filled out has some invalid entries – please correct them before submitting.
你填写的表格有一些无效的条目，请在提交前纠正它们。
The login credentials you provided are invalid; please try again with the correct username and password.
你提供的登录凭据无效，请使用正确的用户名和密码再试一次。