That is not fitting for its purpose / Improper

Third-person singular simple present indicative form of unfit

Not fitful.

plural of unfitness

Not fit; not having the correct requirements. / Not fit, not having a good physical demeanor. / (often with for) Unsuitable for a particular purpose.

To make unfit; to render unsuitable, spoil, disqualify.

Not suited, not fit (for something). / (of a garment, not comparable) Not customized, tailored or cut to fit.

simple past tense and past participle of unfit.

The characteristic of being unfit or ill-suited. / The characteristic of being unfit or out of physical shape.

The quality of being unfitting, or unsuitable.