The story
From hyper- + phantasia; from Ancient Greek φαντασία (phantasía, “perception, impression, image, look, appearance”).
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A condition where one's mental imagery (the mind's eye) is extremely realistic, to the point of confusion with reality. Full definition →
From hyper- + phantasia; from Ancient Greek φαντασία (phantasía, “perception, impression, image, look, appearance”).
Etymology from Wiktionary, CC BY-SA 4.0.