E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Duessa (Double-mind or False-faith).
Daughter of Falsehood and Shame, who assumes divers disguises to beguile the Red Cross Knight. At one time she takes the name of Fidessa, and entices the knight into the Palace of Pride (Lucifera). The knight having left the palace, is overtaken by Duessa, and drinks of an enchanted fountain, which paralyses him, in which state he is taken captive by the giant Orgoglio. Prince Arthur slays the giant and rescues the knight; Duessa, being stripped of her gorgeous disguise, is found to be a hideous hag, and flees into the wilderness for concealment. She appears again in book ii. (Spenser: Faërie Queene, book i. 27; v. 9.)