What is "sneaksby"

Usage examples of "sneaksby".

I hear Buttsy coming on the sneaksby up the stairs, I can see I am taking all the worst of it because I am now wheezing like a busted valve and you can hear me a block away except when I hold my breath, which is very difficult indeed, considering the way I am already greatly tuckered out.

She amused herself by compiling a list of epithets to which Johann might justifiably lay claim: sneaksby, basket-scrambler, hedge-bird.