invalid
UK[ˈɪnvəlɪd]US[ˈɪnvəlɪd]
adj
not legally or officially acceptable
adj
not based on truth or good reasoning; not acceptable
n
a person who needs to be cared for because of illness or disability
Morpheme Breakdown
in
valid
in
not
valid
legally acceptable
Etymology
The word 'invalid' is formed by the Latin negative prefix 'in-' attached to the adjective 'valid'. The root 'valid' originates from Latin validus, meaning strong or effective, itself from the verb valere (to be strong, to be worth). In its original legal and logical sense, something 'invalid' literally means "not strong" or "not effective," and therefore not binding or sound. Over time, this sense of lacking strength or effectiveness was also applied to a person chronically weakened by illness, giving rise to the distinct noun form.
Analysis
Structure: in (not) + valid (legally acceptable)
- in: Latin origin, a prefix meaning "not".
- valid: From Latin validus (strong, effective), from valere (to be strong). In this word, it functions as the root meaning "legally or logically sound".
Examples
The contract was declared invalid by the court.
His argument rests on an invalid assumption.
She has been an invalid since the accident and requires constant care.