A racist term for indian people, describing the thong like underwear that tribes wear, making their asses itchy.
Grandma: Those damn itchybums left their window open all night!
Me: Itchybums?
Grandma: That indian family across the street.
The feeling in your anus after consuming copious amounts of sapporo itchiban noodles.
I just ate 3 packages of noodles. Now I can't get rid of this Sapporo itchybum. Lucky for me, I ate them cooked!