genijalan

1. (of an idea, solution) brilliant; ingenious
   To je genijalna ideja, zašto se nismo ranije setili? — That's a brilliant idea, why didn't we think of it earlier?
   Našao je genijalno rešenje za parking. — He found an ingenious solution to the parking problem.
2. (of a person) of genius; brilliant
   Tesla je bio genijalan naučnik. — Tesla was a brilliant scientist.
3. colloq. awesome; great
   Koncert je bio genijalan! — The concert was awesome!
   Genijalno, vidimo se sutra! — Great, see you tomorrow!

In speech, "Genijalno!" often just means "Great!".