The Spanish word commonly used as a short name for a quinceañera celebration is quince.
Quince is an informal abbreviation of quinceañera, especially in the United States and other places where the event is widely discussed in English and Spanish. It can refer to the entire party rather than only to the person whose birthday is being celebrated.
The shortened term is useful because quinceañera is longer and can describe both the honoree and the occasion. Context usually makes the meaning clear: someone may say “her quince” for the party or “the quinceañera” for the celebrant.
A quince is not simply another word for any birthday party. It specifically evokes the cultural traditions connected with a girl’s fifteenth birthday, though the actual format differs among families. Some include a church service and court of honor; others emphasize music, food, photography, and family celebration.