The usual Spanish singular term for one male attendant in a quinceañera court is chambelán.
Chambelán is the singular form of chambelanes. The word is commonly used for a young man who accompanies the quinceañera in formal parts of the celebration. He may participate in the entrance, posed photographs, and choreographed dances with the rest of the court.
The term is often translated as “chamberlain,” but English-speaking families may use “escort” or another local term. Vocabulary varies across countries and communities, so not every quinceañera uses exactly the same labels.
A chambelán is distinct from a padrino. A padrino is a sponsor or godfather who may help provide items or financial support. One person can occupy more than one role, but the traditional meanings are different: the chambelán belongs to the ceremonial court, while the padrino supports the celebration.