In the phrase “quince años,” años is the Spanish word for “years.”
The phrase literally translates as “fifteen years,” linking the celebration to the honoree’s age. The ñ is important: años means years, while anos without the tilde is a different Spanish word with a vulgar meaning.
Quince años is one of several names used for the tradition. Quinceañera can describe the honoree or the celebration, while fiesta de quince años emphasizes the party itself. Regional and family usage determines which expression is most natural.
The wording also explains why English descriptions often call the event a fifteenth-birthday celebration. Although customs differ across communities, the age-based meaning remains central.