What does invalid mean?
Invalid is an adjective meaning that something is not valid, acceptable, or recognized as legitimate. Its uses range from logical and academic discussion to law, administration, and computing. An argument may be invalid because its reasoning does not follow, while a contract may be invalid because it fails to meet legal requirements or was improperly executed. In technical settings, invalid data or an invalid command is one that cannot be accepted because it violates the system’s required format or rules. The word is generally formal and neutral, though it can sound emphatic when used in place of a less categorical expression such as incorrect. It is especially useful when precision matters, because invalid identifies not merely a mistake or poor quality but a failure to satisfy the standards governing a particular action, document, argument, or system. The related verb invalidate means to cause something to become invalid.
adjectiveNot valid, acceptable, or legally recognized. It may describe something that fails to meet logical, legal, technical, or procedural standards.
- Not logically sound, acceptable, or supported by the relevant rules or evidence.
- Not legally recognized, authorized, or enforceable.
- Not conforming to the required format, structure, or rules for a particular technical system.
"The court ruled that the agreement was invalid because it had never been properly signed."
"His conclusion rests on an invalid assumption."
"The system rejected the form because the address was invalid."
Invalid carries its own “not”: Latin in- means “not,” while validus means “strong, sound, or valid”—so the word originally declared something unfit to stand.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does invalid come from?
Invalid entered English in the early 17th century from the Latin adjective invalidus, meaning “invalid” or “not valid.” The word combines the Latin prefix in- (“not”) with validus (“strong, sound, or valid”), which belongs to the same Latin family as valere, “to be strong.” English relatives such as valid, validity, validate, and valour ultimately trace their histories to this Latin root.
Related word forms
How invalid is actually used
Invalid is formal and widely used in legal, academic, administrative, and technical contexts. In legal writing it can mean void or unenforceable, while in computing it commonly identifies data, code, or a request that does not satisfy a required format or rule.
Easily confused with invalid
Invalid is an adjective describing something that is not valid, while invalidate is a verb meaning to make something invalid.