A girl is a female child or young person. When someone refers to a girl, they usually mean someone who hasn't yet become an adult woman, though the exact age range can be flexible. A five-year-old is definitely a girl, and most people would call a thirteen-year-old a girl too, while a twenty-five-year-old would typically be called a woman.

The word appears constantly in everyday conversation. Teachers might say “the girls and boys in this class,” friends talk about “the new girl at school,” and families have “girl cousins” and “boy cousins.” In stories and movies, you'll encounter girl characters of all kinds: brave girls, curious girls, funny girls, and clever girls.

Sometimes people use girl more loosely. Adult women who are close friends might call each other “girls” when they get together, and someone might say “I'm having a girls' night” to mean spending time with female friends of any age. The word can express closeness and informality in these contexts.

The opposite of girl is boy, and both words simply describe young people of different genders without suggesting anything about personality, interests, or abilities. Girls and boys can be equally good at math, sports, art, science, or anything else they set their minds to.