Definition of quinquagenarian in English:

quinquagenarian

noun

  • A person who is between 50 and 59 years old.

Origin

Early 19th century: from Latin quinquagenarius (based on quinquaginti fifty) + -an.

Pronunciation:

quinquagenarian

/ˌkwɪŋkwədʒɪˈnɛːrɪən/