When you're peeing with incredible force and suddenly fart loudly and unexpectedly
"Oh man...I was just taking a piss and totally had a nendu."
"Jeez, that explains why the guy who came out right before you was holding his nose."
A highly contagious disease that is extremely disgusting and is particular to individuals in the South Asian community. It is best to stay as far away from individuals possessing this disease as possible.
"Yooo, I'm not feeling too good..."
"OH MY GOD! Dude, get the fuck away from me."
"Why, what's wrong?"
"You've got nilaids!"
