cyn dyfod cwbl o’r oed : before the end of the time came
cyn (gynn) : (Konjunktion) sooner, before
dyfod (Verbalnomen von deuaf, doaf | dyfod) : to come
cwbl, cwbwl, cwbyl (m): (hier Genitiv zum Verbalnomen) (the) entire, whole, total
o : (Präposition)
_'r : (bestimmter Artikel)
oed, oyd (pl. oedau, m/) : age; appointed time, respite, delay
Schäfer, Sketch, S. 20