ДОКАЗАТЬ _|_ TO PROVE / DOKAZAT [dəkɐˈzatʲ]  

Hint with an alternative definition: to use decisive docs (documents) or cassette with a caught fact (sartin, certain) for a court of justice, in case of a proof, with consistency and decussate these facts to endorse an indictee.

Hint with composition: doc + to assert something causal + site (of lawyer or attorney) = proof of fault or innocence

Hints with translation + consonant words (by sounds or letters): to cast doze of truth to prove something

Russian pro-tip: до + знак/код + сказать

Mental visualization: ДО (tribune of the judge and the square in front of it) + КАЗ (witnesses who point to the culprit in handcuffs) + ATЬ (then the executioner with the ax meets the culprit)