Meaning of “chaperone” - Learner’s Dictionary

chaperone

noun [ C ] ( also chaperon) uk us /ˈʃæpərəʊn/

an older person who goes somewhere with a younger person in order to make sure they behave well, especially a woman in the past who went with a younger woman who was not married

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