This is one of my favourite words ever.  The noun is pretty nondescript, but the verb is marvellous.  The Oxford Dictionary meaning is to:

“Take (something) for oneself, typically quickly or without permission.”

I have definitely snaffled a lot of stuff in my lifetime.  Items include: fools gold from the house which my parents eventually bought; a candle from C&N Cycles which had the police round my house (long story); copious amounts of food from a variety of places; and pretty much all of my sister’s Easter Eggs every year.

So basically, snaffle is a posh word for stealing.  I should add that the stuff I snaffle these days is much more boring and definitely does not involve the police.