unobtainable (adj.) unobstructed (adj.) unobserved (adj.) unobservant (adj.) unobjectionable (adj.) unnumbered (adj.) unnoticed (adj.) unnerve (v.) unneeded (adj.) unnecessary (adj.) unnatural (adj.) unnamed (adj.) unmuzzled (adj.) unmoved (adj.) unmovable (adj.) unmounted (adj.) unmotivated (adj.) unmoor (v.) unmolested (adj.) unmodified (adj.)