unfit
Meaning
not of the necessary quality or standard to meet a particular purpose
not having the necessary qualities to perform a role or function adequately
to make unsuitable or incompetent
Structure
Usage
the building was declared unfit for human habitation.
his health problems rendered him unfit for military service.
the judge ruled that the evidence was unfit to be presented to the jury.
Etymology
The word "unfit" is a straightforward English formation. The root "fit" entered Middle English from the older English "fitt," meaning a struggle or conflict, which evolved to mean "suitable" or "proper," likely through the sense of being well-matched. The prefix "un-," a prolific negator in English with roots in Old English, is directly attached to this root. The combination literally means "not suitable," a meaning that has remained consistent from its formation to its modern abstract senses describing inadequacy in condition, quality, or competence.
Analysis
un- is a prefix of english origin (old english) meaning "not". fit is a root of english origin (middle english) meaning "suitable" or "proper".