The girl celebrating her fifteenth birthday in a traditional quinceañera is called the quinceañera.
The word is both the name of the celebrant and, by extension, the name commonly given to the celebration itself. In Spanish, the feminine ending identifies a girl or young woman; the masculine form, quinceañero, is used for a boy’s comparable celebration.
A quinceañera is not simply a birthday party in its traditional form. It combines family celebration, religious or ceremonial elements, formal clothing, music, dancing, and symbolic rites that acknowledge a transition toward young adulthood. Customs differ considerably among families and countries, so not every quinceañera includes the same sequence.
The term is especially associated with Mexico, Central America, parts of South America, the Caribbean, and Latino communities elsewhere. English-language usage often keeps the Spanish word, even when the event is held outside a Spanish-speaking country.