An act of removing one's self prematurely at a place or event, especially Applied Differential Equations 1 lecture. A mcglinchey can also occur when the self fails to meet the arrival time, and feels the like the event was a waste of time and that he/she should have not shown up anyways because they assume they know what they're doing.

When some little bitchboy is acting like a little tiny pee pee poo poo baby and messing up the group plans.