The word jit is still used by teens, however, not everywhere. If you check slang circles or look up the jit definition, you’ll notice it is more common in places like Florida or areas influenced by hip-hop. The jit def is still understood as “a young person” or “someone not mature.” The jit def is clear, but the usage depends on where you live. Ha, teens will tell you, but in modern times, it is local rather than universal.