se·lec·tive / səˈlektiv/ • adj. relating to or involving the selection of the most suitable or best qualified: the mini-cow is the result of generations of selective breeding. ∎ (of a person) tending to choose carefully: he is very selective in his reading. ∎ (of a process or agent) affecting some things and not others: modern pesticides are more selective in effect. ∎ chiefly Electr. operating at or responding to a particular frequency.DERIVATIVES: se·lec·tive·ly adv.