1. 无适当根据的　not properly based or able to be upheld by reasoning
2. 无用的，无效的　not usable; not legally recognized
3. 有病的　be ill

　～ argument　没有根据的论点
　～ person　有病的人
　marriage ～　婚姻无效

　This is an invalid assumption.　这是一个无根据的假设。
　He had to look after his invalid brother.　他不得不照看他有病的弟弟。
　Their marriage is invalid.　他们的婚姻是无效的。

C 病人，残疾者person weakened through illness or injury; one who suffers from ill health for a very long time

　visit an ～　看望病人
　bedridden ～　卧床不起的病人
　permanent ～　长期病人

　He will visit an invalid.　他将要去看望一个病人。
　Her grandfather is an invalid.　她的祖父是一个残疾人。

 ♣ invalid, case, patient
　参见patient条。