not conventional; not bound by or conforming to convention, rule, or precedent; free from conventionality: an unconventional artist; an unconventional use of material.
un·con·ven·tion·al (ŭn'kən-věn'shə-nəl) adj. Not adhering to convention; out of the ordinary. un'con·ven'tion·al'i·ty (-shə-nāl'ĭ-tē) n., un'con·ven'tion·al·ly adv.