Invalid
# Invalid

Invalid may refer to:

* Patient, a sick person
* one who is confined to home or bed because of illness, disability or injury (sometimes considered a politically incorrect term)
* .invalid, a top-level Internet domain not intended for real use

As the opposite of valid:

* Validity, in logic, true premises cannot lead to a false conclusion
* Validity (statistics), a measure which is measuring what it is supposed to measure
