Learner's definition of GIRL
1 a : a female child
b : daughter
It's a girl! = She gave birth to a baby girl.
a nine-year-old girl
Ever since I was a (little/young) girl, I've wanted to travel.
2 a : a young woman
b : a usually young woman from a specified kind of place
a group of teenage girls
a 19-year-old girl
His parents hope he'll soon find a nice girl, settle down, and get married.
When she was younger, she was a real party girl. [=a young woman who enjoys parties]
She's a big star now, but her fans still think of her as the girl next door. [=a wholesome young woman from a middle-class family]
3 a the girls : the female friends or work partners of a woman viewed as a group
b [count] : a woman of any age — often used as a friendly way for one woman to address another woman c [count] : a woman or girl who does a particular job or activity
Wait till the girls back home hear about this!
Our boss thinks of herself as just one of the girls.
She went out dancing with the girls.
◊ The use of girl to refer to an adult woman is often considered offensive, especially when it is used this way by a man.
— girlish/ˈgɚlɪʃ/adjective,[more girlish; most girlish]