A term used to accompany the theft of someone's stuff. Not burglary style, but while they are there and not paying attention. Usually for stealing food.
Also a general term of enjoyment, for getting away with something or getting out of a jam.
Group of friends at lunch:
A: Dude, can I have a french fry?
B: No, fuck off.
5 mins later
A: *Takes fry and eats* "Snatchies!"
"Dude, I'm glad that cop was asleep when we blew past him at 90!"
"Yeah especially 'cuz you're not allowed to drive after nine and we're drunk!"
the act of grabbing at something or someone; a grabbing hand gesture that confirms happiness, sweetness, or overall awesome-ocity.
Bob: Dude, did you eat my pudding?
Bob: Is that your banana?