vain > futile; empty
3 Since power of hand, nor skill of learned breast,
skill > knowledge breast > heart; hence: mind
4 Nor worldly price cannot redeem my dear 5 Out of her thraldom and continual fear?
thraldom > slavery
6 For he, the tyrant, who her has in ward
ward > keeping
7 By strong enchantments and black magic lear,
lear > learning, lore
8 Has in a dungeon deep her close embarred,