(noun) The act of inserting a finger within one of the opening (naris) of one's nose with the apparent intent of removing mucus (otherwise known as picking one's nose) esp. when done in public.
A term derived from an episode of Seinfeld.
OMG, do you see what Jerry is doing in that Taxi cab? He seems to be picking his nose.
Maybe, or he's just scraching his nose since I didn't see any nostril penetration.