I've not heard of harelip in those terms either.
Down in Australia, a harelip was the name given to children born with what is now called a cleft lip or cleft palate.

And I have been looking into why it was called that and this is earliest record I found.....very interesting.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1044324/pdf/medhist00013-0055.pdf