1. To suck up or be very nice to your boss or teacher to earn special treatment.
2. To pull down your pants and shove someone's nose into your anal cavity, leaving the tip covered in shit. (Should be done after taking a poop. Not wiping also produces better results.)
1. "Dammit! Johnson wouldn't have gotten that raise if he wasn't such a brown nose."
2. "Ha, Tim was such an asshole yesterday that today on the bus, I gave him a brown nose."
The brown-nose or act of brown-nosing is also when a person removes their pants and underwear and climbs over a sleeping person so that their asshole is approximately 3 inches away from the sleeping person's face. The person performing the act punches the sleeping person in the stomach as hard as possible to wake them up. In theory, the sudden shock of being woken by the punch will cause the sleeper's head to come up and forward, thrusting their nose into the other's ass.
For added 'flavor', the person initiating the act may choose not to wipe after their last bowel movement at which point the act of ''brown-nosing'' can be referred to as the Mexican alarm clock or Sanchez's wakeup call.
some on who is trying to suck up to some one of a higher potision, it is also called bum or ass licking (not to be confused with rimming) and is used to achevie a promotion or high grades