3 Purfled with gold and pearl of rich assay,

Purfled > {Embroidered along the edge; trimmed with metallic lace, pearls, etc.} assay > quality; proven worth

4 And like a Persian mitre on her head

mitre > head-dress; sacerdotal head-dress (often associated with episcopal office or dignity)

5 She wore, with crowns and ouches garnished,

ouches > {Jewels; golden sockets to hold these}

6 Which her lavish lovers to her gave;

lavish > lavish; licentious

7 Her wanton palfrey all was overspread

wanton > playful, unruly; wanton palfrey > {Saddle-horse for ladies}