Up-on, ar, ar uchaf, ar warthaf
Up-per, uch, uwch
Up-right, syth, uniawn, cyfiawn
Up-roar, terfysg, cynhwrf
Up-ward, uwchlaw; i fyny
Ur-chin, draenog, draened
Ur-gent, cymhelliadol, annogol
Us-age, arfer, defod, arferiad; triniaeth
Us-ance, llôg, ocr; gwasanaeth arian
Use-ful, gwasanaethgar, buddiol