unsolved

/ʌnˈsɑːlvd/
adjective
  1. Not having been solved; remaining without an answer or explanation.
    • The puzzle was left unsolved on the table after everyone gave up.
    • Many unsolved mysteries continue to fascinate researchers.
    • The murder case remained unsolved for over twenty years.
Antonyms
What does "unsolved" mean? | whatsthatwordmean | whatsthatwordmean