chaperone
noun /ˈʃæpərəʊn/
  /ˈʃæpərəʊn/
 (also chaperon)
- (in the past) an older woman who, on social occasions, took care of a young woman who was not marriedTopics Historyc2
 - a person who takes care of children in public, especially when they are working, for example as actors                                     
 - (North American English) a person, such as a parent or a teacher, who goes with a group of young people on a trip or to a dance to encourage good behaviour
 
Word Originlate Middle English (denoting a hood or cap, regarded as giving protection): from French, feminine of chaperon ‘hood’, diminutive of chape, from late Latin cappa ‘cap’. The current sense dates from the early 18th cent.