When someone named Megan does something particularly well. This phrase can also be applied to individuals with other names. Can be used when an individual is talking to an attractive person, doing well on school work, or just being fucking awesome in their daily life.
After spending six hours studying, Johnny completely meganated all over that math test.
Megan is talking to that cute guy and getting her meganate on.
Hey yo, you're on a roll, just wanted to point out that you are meganating so hard today.