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.