| UC | ulcerative colitis; ultracentrifugal; umbilical cord; unchanged; unclassifiable; unconscious; undiff... |
|---|---|
| UCS | unconditioned stimulus; unconscious; uterine compression syndrome |
| UD | ulcerative dermatosis; ulnar deviation; undetermined; underdeveloped; unit dose; urethral dilatation... |
| UPS | ultraviolet photoelectron spectroscopy; uninterruptible power supply; uroporphyrinogen synthetase; u... |
| URF | unidentified reading frame; uterine relaxing factor |