Meaning of “parentheses” - Learner’s Dictionary

parentheses

noun [ plural ] uk us /pəˈrenθəsiːz/ (also UK brackets)

two curved lines ( ) used around extra information or information that should be considered as separate from the main part:

The age of each student is listed in parentheses.

(Definition of “parentheses” from the Cambridge Learner’s Dictionary © Cambridge University Press)