“Quince” is a common shortened Spanish name for a quinceañera’s fifteenth-birthday celebration.
The word quince means 15 in Spanish, so the nickname directly highlights the event’s defining age. In English-language Latino communities, people may say someone is having a quince or attending a quince, especially when the longer term is already understood.
The shortened form does not refer to the quince fruit in this context. Spanish distinguishes the number quince from the fruit membrillo or quince, although English spelling can create confusion. Context makes the intended meaning clear.
Usage is informal and varies by country and family. Quinceañera, fiesta de quince años, and quince are all established expressions, but a particular community may prefer one over another.