grudging > being mentally troubled with; hence: resenting

6 As those unknightly railings which he spoke) 7 With wrathful fire his courage kindled bright, 8 Thereof devising shortly to be wreaked,

devising > skilfully preparing; contriving wreaked > avenged

9 And, doubling all his powers, redoubled every stroke.

206.31

Both of them high attonce their hands enhaunst,
2 And both attonce their huge blowes downe did sway;
Cymochles sword on Guyons shield yglaunst,
4 And thereof nigh one quarter sheard away;
But Guyons angry blade so fierce did play
6 On th'others helmet, which as Titan shone,
That quite it cloue his plumed crest in tway,
8 And bared all his head vnto the bone;
Wherewith astonisht, still he stood, as senselesse stone.

1 Both of them high at once their hands enhanced,

at once > simultaneously enhanced > raised

2 And both at once their huge blows down did sway;

sway > swing