odd man out

or odd-man-out


noun

a method of selecting or eliminating a person from a group, as by matching coins, especially in preparation for playing a game.
the person so selected or eliminated.
a game consisting of this method.

Origin of odd man out

First recorded in 1885–90

Idioms and Phrases with odd man out

odd man out

1

A person who is left out of a group for some reason, as in The invitation was for couples only, so Jane was odd man out. [Mid-1800s]

2

Something or someone who differs markedly from the others in a group, as in Among all those ranch-style houses, their Victorian was odd man out. [Late 1800s]