An informal way of complimenting or referring to something big or significant. Particularly something fun, adventurous, or mechevious.
"Hey Chris. You ready to take that rough and unstable car on a 1000 mile road trip!?"
"Yeah man! It's gonna be a butt spankin izz!"

"Dude! You should of seen these cops chase this car going 90mph on the freeway! It was a real butt spankin izz!"
by pnwaccord June 20, 2017
Get the butt spankin izz mug.