girlfriend

girlfriend
girl‧friend S3 /ˈɡɜːlfrend $ ˈɡɜːrl-/ noun [countable]
1. a girl or woman that you are having a romantic relationship with ⇨ boyfriend:
    He’s never had a girlfriend.
    sb’s girlfriend
    He lives in Chicago with his girlfriend.
    split up/break up with your girlfriend (=stop having a romantic relationship)
    one of my ex-girlfriends (=former girlfriends)
    I didn’t have a steady girlfriend (=one you have a long relationship with).
2. especially American English a woman or girl’s female friend:
    She’s out with one of her girlfriends.
     

THESAURUS

   ▪ girlfriend a girl or woman that you have a romantic relationship with, especially for a fairly long time: Katherine was his first girlfriend.
   ▪ partner the person you are married to, or the person you are living with and having a sexual relationship with: He brought his partner along to the party.
   ▪ old flame informal someone who was your girlfriend or boyfriend in the past: I found a love letter from one of his old flames.
   ▪ mistress a woman that a man has a sexual relationship with even though he is married to someone else. Often used when the man is famous or powerful: The president had a mistress for many years.
   ▪ lover someone who you have a sexual relationship with, but who you are not married to: He was going to meet his secret lover.
   ▪ fiancée the woman who a man is going to marry: Rod plans to marry his fiancée later this year.
   ▪ ex informal a man's former wife or girlfriend: My ex looks after the children on Thursdays.
   ▪ be going out with somebody if you are going out with a girl or woman, she is your girlfriend: She's going out with a guy she met at work.