4 Whom ravenous hunger did thereto constrain:

thereto > to that [roaring]

5 Then gan he toss aloft his stretched train,

gan > did train > tail

6 And therewith scourge the buxom air so sore,

therewith > with it buxom > yielding, pliant

7 That to his force to yield it was fain;

fain > obliged

8 Neither aught his sturdy strokes might stand before,

aught > anything sturdy > recklessly violent might stand before > could withstand