Or-chard, perllan, afallach
Or-dain, gosod, trefnu; urddo
Or-der, trefn, rheol: trefnu; erchi
Or-ders, gorchymmynion; urddau
Or-gan, organ; offeryn, peiriant
Or-phan, plentyn amddifad; amddifad
Os-trich, estrys
Oth-er, all, arall, llall
Ot-ter, dyfrgi, dwfrgi
O-val, hirgrwn, wyfal