Is it farther or further?
early 15c., from Old French antelop, from Medieval Latin ant(h)alopus (11c.), from Greek antholops (attested in Eusebius of Antioch, c.336 C.E.), a fabulous animal haunting the banks of the Euphrates, very savage, hard to catch and having long saw-like horns capable of cutting down trees. Original sense and language unknown (it looks like Greek "flower-eye," as if from anthos + ops, but that may be a result of Greek folk etymology). A heraldic animal, also known in Medieval Latin as talopus and calopus, the name was applied c.1600 to a living type of deer-like mammal. In the western U.S., it is used in reference to the pronghorn.