unpretentious (adj.) unpresentable (adj.) unprepossessing (adj.) unprepared (adj.) unpremeditated (adj.) unprejudiced (adj.) unpredictable (adj.) unprecedented (adj.) unpracticed (adj.) unpopularity (n.) unpopular (adj.) unpolluted (adj.) unpolished (adj.) unplug (v.) unpleasantness (n.) unpleasant (adj.) unplanned (adj.) unplace (v.) unperturbed (adj.) unpersuasive (adj.)