giantess (plural giantesses) A female giant. 1590, Edmund Spenser, The Faerie Queene, III.7: He spide far off a mighty Giauntesse / Fast flying, on a Courser dapled gray […] 1926, Enid Blyton, The Book of Brownies The giantess picked him up and gave him such a squeeze that he felt he was going to choke.