The story
Word created by Charles Howard Hinton, in his book A New Era of Thought published in 1888, from Ancient Greek tessara- (“four-”) + Ancient Greek ἀκτίς (aktís, “ray”).
Etymology from Wiktionary, CC BY-SA 4.0.
tesseract
Today it means: The four-dimensional analogue of a cube; a 4D polytope bounded by eight cubes (analogously to the way a cube is bounded by six squares). Full definition →