the soft patch of skin that is located between the scrotum and the anus. usually very wrinkled and has a tinge of brown due to it's close proximity to the anus. Its name derives from part scrotum + part anus = scrainus
example a: yesterday i had a terrible itch on my scrainus.
example b: dont you think paul bettinger's face looks like a scrainus?
by jfreakind August 24, 2007
Get the scrainus mug.