As > [As if]
fast > rapidly; very closely

3 And her fair yellow locks behind her flew,
4 Loosely dispersed with puff of every blast:
5 All as a blazing star does far outcast

blazing star > comet
outcast > cast out; _hence:_ emit

6 His hairy beams, and flaming locks dispread,

dispread > extend

7 At sight whereof the people stand aghast:
8 But the sage wizard tells, as he has read,

read > foreseen, divined; foretold

9 That it importunes death and doleful drearihead.

importunes > imports, portends (catachr. SU)
drearihead > dreariness, grief

301.17

So as they gazed after her a while,
2 Lo where a griesly Foster forth did rush,
Breathing out beastly lust her to defile:
4 His tyreling iade he fiercely forth did push,
Through thicke and thin, both ouer banke and bush
6 In hope her to attaine by hooke or crooke,
That from his gorie sides the bloud did gush:
8 Large were his limbes, and terrible his looke,
And in his clownish hand a sharp bore speare he shooke.

1 So as they gazed after her a while,
2 Lo where a grisly foster forth did rush,

grisly > horrible, fearsome
foster > forester

3 Breathing out beastly lust, her to defile:

defile > debauch, violate

4 His tireling jade he fiercely forth did push,

tireling > {A tired animal}
jade > nag, hack (cf. 211.31:2)

5 Through thick and thin, both over bank and bush
6 In hope her to attain by hook or crook,
7 That from its gory sides the blood did gush:

That > [So that]
blood > (Raised by the foster's spurs)

8 Large were his limbs, and terrible his look,
9 And in his clownish hand a sharp boar-spear he shook.

clownish > clumsy, peasant's
shook > wielded

301.18

Which outrage when those gentle knights did see,
2 Full of great enuie and fell gealosy,
They stayd not to auise, who first should bee,
4 But all spurd after fast, as they mote fly,
To reskew her from shamefull villany.
6 The Prince and _Guyon_ equally byliue
Her selfe pursewd, in hope to win thereby
8 Most goodly meede, the fairest Dame aliue:
But after the foule foster _Timias_ did striue.

1 Which outrage when those gentle knights did see,

gentle > noble; courteous

2 Full of great envy and fell jealousy,

envy > enthusiasm; _or, perhaps:_ malice [directed at the foster]
fell > terrible, fierce
jealousy > eagerness to serve; anger, indignatio