Two entries with the name Argante.
Argante
The Queen of Avalon (in Layamon), a “radiant elf,” to whom Arthur went after his last battle at Camlann.
The name Argante may be a corruption of Morgan, who is traditionally the queen that receives Arthur’s body. It has been suggested that she was a form of the British goddess Arianhrod.
See also
Elves | Myths and Legends
Source
Brut | Layamon, late 12th century to mid-13th century
Argante
A giantess who was the daughter of a Titan. She lived in incest with her brother, Ollyphant, but her insatiable lust drove her to enslave men whenever she found them. The knight Satyrane tried to slay her but was knocked unconscious.
See also
Titans | Myths and Legends
Source
The Faerie Queene | Edmund Spenser, 1570-1599