3 With goodly grace and comely personage,

goodly > attractive, beautiful personage > {The body and appearance as distinct from clothing}

4 That was on earth not easy to compeer;

compeer > equal, rival

5 Full of great love, but Cupid's wanton snare

Cupid > (God of love, the son of Jupiter and Venus)

6 As hell she hated, chaste in work and will; 7 Her neck and breasts were ever open bare, 8 That ay thereof her babes might suck their fill;

ay > ever, always

9 The rest was all in yellow robes arrayed still.

yellow > (The colour of fertility: see Met. 10.1) still > ever, always