An object or person that does not fit in. Commonly used for people that don't fit the norm in a given environment. A redsmurf can be anything from a jock in a room of nerd, or a nerd in a room of jocks.
What the hell is that guy doing here at the party. Hes such a redsmurf.
A redsmurf is an individual that does not fit in. This is a play on the cartoon smurfs. As you can imagine if there was a red smurf in the cartoon, he/she would have been out of place.
I felt like a redsmurf wearing my speedo to the club.