thirty something

/ˈθɜːrtiˌsʌmθɪŋ/
adjective
  1. Relating to or characteristic of a person in their thirties.
    • He bought a thirty-something wardrobe that was stylish but not too trendy.
    • Her thirty-something energy surprised everyone at the marathon.
    • The magazine targets a thirty-something audience with articles on finance and fitness.
noun
  1. A person whose age is between 30 and 39, or the age range itself.
    • She wrote a novel about the struggles of a thirty-something in the city.
    • Many thirty-somethings are balancing young children with demanding jobs.
    • The party was full of thirty-somethings chatting about careers and mortgages.