Think-ing, meddyliad, myfyriad; myfyriol
Thirst-y, sychedig
Thir-ty, deg a'r hugain, trideg
This-tle, ysgallen, ysgellyn
Thith-er, hyd yno
Thor-ough, cyflawn, hollol, perffaith
Thought-ful, myfyrgar, meddylgar
Thous-and, mil, deg cant
Thral-dom, caethiwed, caethwasanaeth
Thrash-er, dyrnwr, ffustiwr