A girlfriend is a girl or woman who is someone's romantic partner. When two people are dating and have chosen to be in a relationship together, they might call each other boyfriend and girlfriend. Being someone's girlfriend means you care about each other in a special way, spend time together, and support each other.

The word can also simply mean a female friend, especially when girls or women talk about their friends. A woman might say, “I'm meeting my girlfriends for lunch,” meaning she's getting together with her female friends. The context usually makes it clear which meaning is intended.

In the romantic sense, being a girlfriend involves trust, kindness, and treating each other with respect. Young people sometimes use the term more casually, like saying someone is “my girlfriend” even if they just like each other and aren't in a serious relationship yet. As people get older, the term usually suggests a more committed relationship, though not as formal as being engaged or married.