unfit

adjective

1. not fit; not adapted or suited; unsuitable: He was unfit for his office.
2. unqualified or incompetent.
3. not physically fit or in due condition.
4. Biology. pertaining to an organism or population that is not adapted to prevailing conditions or is not producing offspring in sufficient numbers to maintain its contribution to the gene pool of the next generation.

verb (used with object)

5. to render unfit or unsuitable; disqualify.

adjective

1. (postpositive often foll by for) unqualified, incapable, or incompetentunfit for military service
2. (postpositive often foll by for) unsuitable or inappropriatethe ground was unfit for football
3. in poor physical condition

adj.1540s, “not suitable” (in reference to things), from un- (1) “not” + past participle of fit (see fit (adj.)). Related: Unfitness. In reference to persons or human qualities, attested from 1550s. The verb meaning “to render unfit” is recorded from 1610s.