stay > hold back
2 And with fair treaty pacified their ire;
treaty > speech, negotiation; entreaty, persuasion
3 Then, when they were accorded from the fray,
accorded > reconciled
4 Against that castle's lord they gan conspire,
gan > did
5 To heap on him due vengeance for his hire.
hire > reward
6 They been agreed, and to the gates they go