What is a "sploik"

I think the proper word--if you can call it one, is "spoink!", but there is already a blog out there using it. I got it from the lovable character Pinky, of "Pink and the Brain". He was always throwing out these verbalisms that just made me chuckle--and, to many a worrying friend's dismay, mimic.

Anyway here it is. Nuff!