revest > reinstate; dress, apparel ("her" being understood from line 7) due habiliments > appropriate attire
201.23
For all he did, was to deceiue good knights,
2 And draw them from pursuit of praise and fame,
To slug in slouth and sensuall delights,
4 And end their daies with irrenowmed shame.
And now exceeding griefe him ouercame,
6 To see the Redcrosse thus aduaunced hye;
Therefore this craftie engine he did frame,
8 Against his praise to stirre vp enmitye
Of such, as vertues like mote vnto him allye.
1 For all he did was to deceive good knights, 2 And draw them from pursuit of praise and fame, 3 To slug in sloth and sensual delights,
slug > laze; waste time
4 And end their days with irrenowned shame.
irrenowned > infamous (WU)
5 And now exceeding grief him overcame, 6 To see the Redcross thus advanced high;
advanced > raised; extolled (referring either to the knight or his heraldic bearing, the red cross)
7 Therefore this crafty engine he did frame,