Ms.Sellas Posted in M Best definition Ms.Sellas Me. Sellas is a horrible teacher she is extremely mean and harsh if you are going to further grade or is in fourth grade hopefully you don’t get a Me. Sellas Student:Ms.sellas is so mean. How satisfied are you with the definition? Looking for Ms.Sellas meaning? Delighted that you discovered the greatest determine on our web site! Recently this definition was actually observed 34 times.