Definition of young at heart in English:

young at heart

adjective

  • Especially of middle-aged or elderly people: having qualities associated with young people, especially energy, enthusiasm, or optimism.

noun

  • Treated as plural. With the: young at heart people as a class.

Origin

Mid 19th century; earliest use found in Albion. From young + at heart.

Pronunciation

young at heart

/ˌjʌŋ ət ˈhɑːt/