The word "harelip" is a term used to describe a birth defect where a person has a split in their lip. It is called "harelip" because the split resembles the cleft in a hare or rabbit's lip. Full definition
We note the addition of folic acid which can help pregnant dogs avoid producing puppies with harelips and cleft palates. (dogfoodinsider.com)
He's liable to hit it as hard as he can and harelip somebody but maybe they'll pick it up and throw him out for you and you've been lucky. (si.com)
There he proves no match for his tough sheriff brother Dan (James Badge Dale), let alone the villainous outlaw Butch Cavendish (William Fichtner, acting with a prosthetic harelip) or duplicitous civic leader Cole (Tom Wilkinson), who stands to make a killing when the railroad comes through. (bostonglobe.com)