1 He, seeing with that churl so fair a wight,

churl > bumpkin, boor, low fellow wight > creature, woman

2 Decked with many a costly ornament, 3 Much marvelled thereat, as well he might,

thereat > at that

4 And thought that match a foul disparagement:

disparagement > {Marriage to one of inferior rank; the disgrace occasioned by this}

5 His bloody spear eftsoons he boldly bent

eftsoons > thereupon bent > brought to bear

6 Against the silly clown, who, dead through fear,

silly > silly; helpless clown > yokel, peasant; clown