Redshirt Girlfriend 

1. A girl aspiring to become your girlfriend.

2. The Girl that a guy keeps around in waiting as a back-up to his current girlfriend. Similar to a Sancha or the other woman, however calling a girl a redshirt girlfriend does not neccessarily imply that she has had relations with the guy while he was with the previous girlfriend.

etymology: a Redshirt Freshman is an american college football term for an athlete who practices with the team, but sees little game time in order save a year of eligibility to play for his team at a later date.

Definition 1- Man, that girl Kelly is all over you dude. I think she is your Redshirt girlfriend.

No one knew why Billy dropped his girlfriend Sally until everyone found out about his Redshirt Girlfriend, Gloria.

Redshirt Girlfriend by The Mahatma December 26, 2008

Redshirt Girlfriend 

The woman on the sideline ready to jump in the sheets during the week that your wife or girlfriend is on the rag. Similar to a Sancha or the other woman.

Man my girl's ragging again. Time to hit up the Redshirt girlfriend.

Redshirt Girlfriend by HOLEEFUKS November 17, 2015