My grandparents are still very 'youthful'.
He's a 'youthful' 50-year-old.
a 'youthfully' energetic group
(..) It was Thanksgiving, . I met the person who changed my life forever. Well, Benjamin... Might I say you are looking strikingly youthful. Good day, Mrs Fuller. A single cane, back straight as an arrow... What elixir have you been drinking? (..)2008 The Curious Case of Benjamin Button