Rust (2010) (edit Kotlin (2011) perhaps), but point being there aren't many newer: https://en.wikipedia.org/wiki/Timeline_of_programming_langua...
That metric is subjective and arbitrary, but it's on my mind because my company is hiring for clojure developers (see my immediate comment history & apologies for the advertisement).
And it's on my mind because common lisp and scheme are _old_.
One of the nicer things about clojure is relatively frequent mentions of how common lisp did things, then a choice to hew or differ. And common lisp and the lisp family of languages have a long history. I like this as an art-piece of lisp's age: http://kazimirmajorinc.com/Documents/Lisp-code-typography/in...