This is the 9345th most frequent Polish word.
ukryto
"Ukryto" means "hidden" in English.
In this sentence, 'ukryto' functions as a third-person singular, past, passive verb form indicating that the treasure has been concealed.
Skarb ukryto głęboko pod zamkiem.
The treasure was hidden deep under the castle.
Here, 'ukryto' once again acts as a passive verb, emphasizing the action of hiding the evidence without specifying who performed the action.
Dowody ukryto przed oczami wszystkich.
The evidence was hidden from everyone's sight.
Similar to the previous sentences, 'ukryto' is used in the passive voice to describe an action where the subject (the key) is concealed.