An instance in which you haven't jacked-off in a very long time, thus resulting in the shooting of a very large and creamy load, usually on the face or chest. Over-ejaculation does not not exceed 11 fluid ounces. For a larger amount, see uber-ejaculation.
When my mom saw that my wall was covered semen, I explained that it was the result of over-ejaculation, so she gave me a cookie.
by Gary Coleman IV June 17, 2008