not fit; not adapted or suited; unsuitable

He was unfit for his office.

unqualified or incompetent.

not physically fit or in due condition.

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.

to render unfit or unsuitable; disqualify.

adjective

appropriate , fit , suitable , able , qualified , ready , willing

adjective

below par * , can’t make the grade , debilitated , decrepit , discordant , down , dragging , feeble , flimsy , ill-adapted , ill-equipped , ill-suited , improper , inadequate , inapplicable , inappropriate , incompatible , incongruous , incorrect , ineffective , inexpedient , infelicitous , inharmonious , laid low , mistaken , not fit , out of element , out of place , out of shape , poorly , rocky * , unbecoming , uncongenial , uncool , unhealthy , unlikely , unmeet , unpromising , unsuitable , unsuited , useless , valueless , amateur , awkward , blundering , bungling , bush league * , butter-fingered , clumsy , disqualified , heavy-handed , impotent , incapable , incapacitated , incompetent , inefficient , ineligible , inept , inexperienced , inexpert , maladjusted , maladroit , no good , not cut out for , not equal to , not up to , unable , unapt , unfitted , unhandy , unpracticed , unprepared , unproficient , unqualified , unskilled , unskillful , untrained , weak , inapt , malapropos , unbefitting , unseemly , unequal , disabled , faulty , handicapped , sick , sickly

verb

disable , disqualify