So-no-rous, seinfawr, soniarus

Sooth-say-er, dewin, dewinwr

Soph-is-try, twyllresymiad

Sor-cer-er, swynwr

Sor-cer-y, swyngyfaredd

Sor-row-ful, trist, galarus

Sov-er-eign, penllywydd; penadur; goruchaf, goruchel

South-er-ly, deheuol

Spe-cif-ic, priodfeddyginiaeth; priodol, neillduol

Spe-ci-fy, penodi, gwahanodi