9 Did him at once oppress, and vex his caitiff spirit.

at once > simultaneously; immediately oppress > overwhelm caitiff > wretched, despicable, servile

310.18

Long thus he chawd the cud of inward griefe,
2 And did consume his gall with anguish sore,
Still when he mused on his late mischiefe,
4 +Then+ still the smart thereof increased more,
And seem'd more grieuous, then it was before:
6 At last when sorrow he saw booted nought,
Ne griefe might not his loue to him restore,
8 He gan deuise, how her he reskew mought,
Ten thousand wayes he cast in his confused thought.

4 Then > So 1590

1 Long thus he chawed the cud of inward grief, 2 And did consume his gall with anguish sore;

gall > (Rancour was said to have its seat in the gall)

3 Still when he mused on his late mischief,

Still > Ever, continuously late > recent mischief > misfortune, disaster

4 Then still the smart thereof increased more,