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.

Noun: a friend who is usually only called upon by a friend when a more primary/prominent friend is unavailable.

Taken from the term “second string” in an athletic competition situation. In football, if the star quarterback gets injured during a play, the second string is called off the bench to replace him/her. A “Second String Friend” is essentially benched until needed, if ever.

Synonyms: Plan B, Second Choice, Secondary Friend, Benched Until Needed

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.