Pre-cinct, cylchran, terfyn
Pre-cious, gwerthfawr, drud
Pre-cise, pendant, penodol; cywir
Pre-clude, rhagrwystro, rhagattal
Pre-dict, rhagfynegi; daroganu
Pref-ace, rhaglith: rhagymadroddi
Pre-fect, rhaglaw
Pre-fer, dewis o flaen, blaenberchi
Pre-fix, blaenddod, arddodiad: darddodi
Preg-nant, beichiog; ffrwythlawn