A female partner in an unmarried romantic relationship.
Marc went to the park with his girlfriend and watched the sunset with her.
I was playing the acoustic guitar and my girlfriend was playing the drums.
(somewhat dated) A female friend of a woman or girl.
Mary always enjoyed hanging out with her girlfriend Jessica.
(LGBTQ) A fellow gay man, especially a friend as opposed to a sexual partner.
[Tim:] james huh? my lover carlos's best girlfriend is named james.
[James:] yes, i know. i AM your lover carlos's best girlfriend james.
A term of address for a female friend or among gay men.
[Hanque:] girlfriend - how'r we doing?
[Doug:] hi hanque, i'd like a capuccino and some lobster bisque..
[Caption:] (friendliness with the waitstaff is a good sign)