1.) The dead skin yielded under your
fingernails after
scratching your buttocks.
2.) To scratch your posterior.
To skinass too hard or too often would be ill-advised, as you may end up
developing poop finger.
Shaun headed to the nearest restroom after
noticing he had a case of skinass on his hands.
Jordan always skinasses right when he gets out of bed
in the morning. He may be
developing a rash.