1 But nothing might relent her hasty flight;

might relent > could slacken

2 So deep the deadly fear of that foul swain

swain > bumpkin, yokel; the word is also a legal term: freeholder within the forest, hence: forester

3 Was erst impressed in her gentle spirit:

erst > lately, previously; first

4 Like a fearful dove, which through the reign

reign > realm, dominion

5 Of the wide air her way does cut amain

amain > at full speed