"Unicorn" is a perfectly literal and correct translation of the Greek for an audience that does not take it to refer to a mythical horse with a magical horn. As I already explained above, modern research has given good reason to think "aurochs" or "wild ox" is the intended meaning. If you have any more questions and still insist on making it all about an outdated translation that for most people now needs a translation itself, please first read <em>Idylls of the King</em> and submit a minimum 600-word essay citing examples of Tennyson's use of deliberately archaic English and explaining why you think he chose to do so.