Ülikõva
Ülikõva is an Estonian slang term that translates roughly to "super hard" or "extremely tough." It is used to describe something that is exceptionally difficult, challenging, or demanding. This can apply to a variety of situations, such as a difficult exam, a physically demanding task, or a complex problem. The term conveys a sense of admiration for the sheer difficulty or resilience involved.
The word is a compound of "üli," a prefix meaning "super" or "very," and "kõva," meaning "hard"