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1. red shirt
A character in a science fiction or adventure story whose sole dramatic purpose is to get killed by the story's villain and/or intinerant monster.

Taken from the propensity of security officers on the original Star Trek series (who typically wore red uniform tops) to be killed in the epsiodes' pre-opening-credits teasers.
Methinks Lt. Jones is doomed to be just another red shirt.
2. Red Shirt
Walk on player to college team, on team, does not play in games for one year to save a year of eligibility.
Even though the red shirt running back is the better one, he doesn't play because he is a red shirt; if he plays he'll give up a year of eligibility.
3. red shirt
In star trek episodes,the expendible crew member who always dies wears a red shirt .so that it has come to mean the failure or defeat of an idea or action.
Thats a good idea but, corporate is sure to red shirt it.
4. red shirt
A Navy term used to describe a person who's job is in Aviation Ordnance on an aircraft carrier flight deck. An ordnanceman.
If you see the 'Red Shirts' running, keep up.
5. red shirt
In college athletics, a red shirt is a player that is on the team, but hasn't played in a game yet.

One of the previous posters is incorrect about red-shirts being walk-ons. Scholarships players are red-shirted all the time.
Johnny was given a scholarship to play quarterback, but was told by the coach that he would red shirt his freshman year until he learned the system.
6. Red Shirt
A bouncer at the Longbranch in Saskatoon, Saskatchewan

ALSO

What to say when an undesirable person is bothering you or a fight has broken out at the Longbranch in Saskatoon, Saskatchewan
"Don't make me red shirt you!"

"Hey red shirt! There's a fight!"
7. Red shirt
Very attractive young female that has yet to reach the age of consent.
Guy 1: See the red shirt over there, she's smokin'!
Guy 2: Don't you think she's a little too young?
Guy 1: Yeah, I know, She's a red shirt, not on this seasons roster.