gan > did; began (… to) wax > grow, become wood > furious

7 And him affronted with impatient might:

affronted > confronted; faced in defiance impatient > impatient (from Pyrochles's viewpoint); unendurable, insufferable (from Furor's viewpoint)

8 So both together fierce engrasped be,

engrasped be > [were grasped; grappled]

9 While Guyon, standing by, their uncouth strife does see.

uncouth > bizarre; unseemly

205.21

Him all that while Occasion did prouoke
2 Against Pyrochles, and new matter framed
Vpon the old, him stirring to be wroke
4 Of his late wrongs, in which she oft him blamed
For suffering such abuse, as knighthood shamed,
6 And him dishabled quite. But he was wise
Ne would with vaine +occasions+ be inflamed;
8 Yet others she more vrgent did deuise:
Yet nothing could him to impatience entise.

7 occasions > occasion 1609