1 And sooth, men say that he was not the son

sooth > truly, in truth

2 Of mortal sire, or other living wight,

sire > father wight > creature

3 But wondrously begotten, and begun

begun > brought into being

4 By false illusion of a guileful sprite,

sprite > (See HRB 6.18)

5 On a fair lady nun, that whilom hight

whilom > formerly, of old hight > was named