Un-ti-dy, digryno, annhaclus
Un-time-ly, annhymig, anamserol
Un-whole-some, afiachus, aniach
Un-wil-ling, anewyllysgar, anfoddog
Un-wor-thy, annheilwng, anwiw
Up-per-most, uchaf, uchelaf
Up-right-ness, uniondeb, gonestrwydd
Ur-gen-cy, anghenrhaid, dirni
Use-ful-ness, defnyddioldeb
U-su-al, arferol, cyffredin