Almost-Girlfriend 

Someone you are seeing for awhile, and even though you get introduced to her friends and family and spent valentine's day weekend with her in scenic cabin out somewhere, she still won't be referred to as "girlfriend". There can be almost-boyfriends, too, I suppose.

Yesterday I went to the wedding of my almost-girlfriend's cousin and her mother asked me if my knee is doing better.

Almost-Girlfriend by colleague June 11, 2009

Almost girlfriend 

The girl who almost became your girlfriend but something happened meanwhile and you just lost her.

Your friend sees a hot girl and says dude look at her...

You say dude she was in my high school and she was my almost girlfriend.

Almost girlfriend by Vrehaan January 5, 2012