gentle > gentle; noble squire > attendant
2 That lady's love to his lord forlent,
forlent > gave up, relinquished (this form not in OED)
3 And with proud envy, and indignant ire,
envy > enthusiasm, desire
4 After that wicked foster fiercely went.
foster > forester
5 So been they three three sundry ways bent.
been > [were] bent > bound, directed
6 But fairest fortune to the prince befell, 7 Whose chance it was, that soon he did repent,