mcglynning it 

When someone inhales smoke incorrectly (be it tobacco or something else), and subsequently chokes.

Boy 1: *smokes + coughs*
Boy 2: dude you just mcglynned it!

or

Boy 1: why is that guy coughing?
Boy 2: because he just failed to smoke so he's mcglynning it

mcglynning it by ibpro November 21, 2010

McGlynning It 

When you try to inhale any type of smoke properly and fail resulting in a coughing fit.

Guy1: Wow she's coughing at lot, is she ok?
Guy2: She's fine, she just McGlynned her fag

or

Guy1: Can i have a toke of that?
Guy2: Only if you don't McGlynn it, there isn't much left

or

Guy1: Can i scrape a fag?
Guy2: Nah, you're always wasting them by Mcglynning it!

McGlynning It by DI Girl November 21, 2010