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?
The area between an individual's penis shaft and scrotum. Often itches and is relieved through very accuratescratching.
Dude: Dude, I scratched my scronus for like 2 hours this morning Other Dude: Dude! Mine itched for so long the other day! It felt awesome scratching it!