Horse, Car, Cursor, Courier... same thing
The primary sense of all these words (horse, car, cursor, etc) is to run. HRS/KRS. Latin: curro, I run. Cursor: one who runs. Cursive: running writing. Courier: person who runs with something. Car: a thing that runs. Once it goes north the K becomes an H as per Grimm's law, e.g. Lating Cardio (heart), Canem (Hound), Cent (Hundred), etc. So, Hrs is from Krs, ie Horse is from Curs* (to run).