vengeable > {Characterized by or arising from revenge; cruel, dreadful} despite > outrage; rage; malice
4 To punish: yet it better first, I thought,
punish > inflict [by way of punishment]
5 To wreak my wrath on him that first it wrought. 6 To Philemon, false faitour Philemon,
faitour > impostor
7 I cast to pay that I so dearly bought;
cast > decided, resolved that > [that which] dearly > grievously; expensively
8 Of deadly drugs I gave him drink anon,
drink > [to drink] anon > straightway; (catachr.) soon
9 And washed away his guilt with guilty potion.