Soft loose clothes worn when you definitely wont be leaving the house, worn for warmth and comfort usually over pyjamas. A jogging suit that has never or will never be jogged in.
The act of getting into ones snugglesuit is known as "snuggling up"
" Fuck the pub its pissin down, its my snugglesuit and that big bag of sticky green till the bastard sun comes back out"
Snigglefritz is a word originating from 17th century Stephish. It's origin also helps define it's meaning. A snigglefritz is a pink sock which is placed over an erect male sexual organ to keep it warm in times of severe cold.
A snigglefritz is also a bunny.
Wow, it's quite nipply, fetch me my snigglefritz!
or
Look at that family of snigglefritz sitting by the way side.