Meaning of odd man out

odd' man" out'

Pronunciation: [key]
  1. a method of selecting or eliminating a person from a group, as by matching coins, esp. in preparation for playing a game.
  2. the person so selected or eliminated.
  3. a game consisting of this method.
  4. outsider (def. 2).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.