noun, feminine/ˌkinθeaˈɲeɾa/plural: quinceañeras
female equivalent of quinceañero: fifteen-year-old (girl); quinceañera (fifteenth birthday celebration for a young woman)
Synonyms: fiesta de quince años, fiesta de quince, quinceaños
From quince años (“fifteen years”) + -era, with implied fiesta (“party”) when referring to the celebration.