look up any word, like plopping:
 
1.
When a girl has a great body and totally do-able, but her face looks like some kind of lagoon creature that has spawned from the combined hatred of the world into a tangible cluster-fuck of GOO!
She is so heinous that you would rather chop off her head and replace it with a Jack-o-lantern, take care of your business and then move on with your life. Hence the word 'Jackie.'
Jackie's are most commonly girls that you only see from behind and first and are misled to think is hot.
Sean: Dude that chick is seriously hot.
Adam: Which one?
Sean: The one over there with her back to us.
(She turns around)
Adam: Aw! She's a Jackie.
by David Atkins March 11, 2011