That person you know who spends his whole life telling ludacris lies to try and fit in with the cool people.
You can tell if a person is a mcnick because they tell completely bullshit and rediculous stories. they also are commonly seen having gay conversations about how cool they are. they also recite the emo alphabet. they often make wacked out stories when late to social gatherings. e.g.

A person with an outwardly dominant, masculine, or aggressive personality, but who also enthusiastically takes on the submissive or "bottom" role in the bedroom.