un·fit / ˌənˈfit/ • adj. 1. (of a thing) not of the necessary quality or standard to meet a particular purpose: the land is unfit for food crops. ∎ (of a person) not having the requisite qualities or skills to undertake something competently: she is unfit to have care and control of her children. ∎ Biol. (of a species) not able to produce viable offspring or survive in a particular environment. 2. (of a person) not in good physical condition, typically as a result of failure to exercise regularly.• v. (-fit·ted , -fit·ting ) [tr.] archaic make (something or someone) unsuitable; disqualify.DERIVATIVES: un·fit·ly adv.un·fit·ness n.