MASP Posted in M Best definition MASPcollege Middle-Aged Smarty Pants: an older over-achiever, smart, educated, and still learning. “Susie went back to school for her PhD at age 45. She’s such a MASP.” How satisfied are you with the definition? Looking for MASP meaning? Delighted that you discovered the greatest determine on our web site! Recently this definition was actually observed 25 times.