To have diarrhea, and you shit so hard it rebounds off the toilet lid and lands up your back
last night i shit so hard i got back spackle up to my neck
by the mail man November 07, 2007
More of a sniglett, but is very commonly known as the black streak build-up of wet road debris (mostly dirt & who knows what else) that collects on the back of your shirt or coat as you ride a bicycle in the rain.
My jacket was streaked in backspacle from the water coming off of my back bicycle tire after riding in the rain for hours.
by Zeekophobe December 13, 2003
After defiling your old lady’s ass doggie style, pull out your pud before you cum, and spray your jizz all over her lower back.
I love to back spackle on my old lady's tattoo.
by CrackSabbath September 09, 2003