Question

invalid 【invalid】adj.无效的；Unless a check is signed, it is invalid.支票除非签了名，否则是无效的。

Accepted Answer

[ɪn'vælɪd] 
invalidno longer valid
A person who is very sick or injured and needs frequent care is an invalid. Also, something no longer current or useful is invalid.
The main uses of this word have to do with people and things that don't work very well anymore. A driver's license that has expired is invalid — it needs to be renewed. If you lost your health insurance, it's invalid. People who are called invalids are disabled or incapacitated severely. Be careful with this word, because some think it is inappropriate, since it sounds as if some people are not as valid as others based on physical capability.
All forms of 'invalid' will appear on average once every 531 pages.invalidisminvalidityinvalidnessinvalidatedinvalidatinginvalidationinvalidvalidvalidatevalidityvalidlyvalidnessinvalidatevalidatedvalidatingvalidationvalidatory

Front	invalid
Pron	[ɪn'vælɪd]
Back	【invalid】 adj.无效的； Unless a check is signed, it is invalid. 支票除非签了名，否则是无效的。
Vocab	invalidno longer valid A person who is very sick or injured and needs frequent care is an invalid. Also, something no longer current or useful is invalid. The main uses of this word have to do with people and things that don't work very well anymore. A driver's license that has expired is invalid — it needs to be renewed. If you lost your health insurance, it's invalid. People who are called invalids are disabled or incapacitated severely. Be careful with this word, because some think it is inappropriate, since it sounds as if some people are not as valid as others based on physical capability. All forms of 'invalid' will appear on average once every 531 pages. invalidism invalidity invalidness invalidated invalidating invalidation invalid valid validate validity validly validness invalidate validated validating validation validatory

Invalid People Longer Valid ɪn'vælɪd Adj.无效的 Check Signed