Noun form of 'guilty' is -

Explanation: Guilt (noun): দোষ; অপরাধ; অপরাধিতা।
English Meaning: The state of one who has committed an offense especially consciously. 
Example Sentences: 
- The jury determines the defendant's guilt or innocence.
- His guilt in the matter was indisputable.
- It was clear that the guilt lay with him.

Guilty (adjective): Justly chargeable with or responsible for a usually grave breach of conduct or a crime. 
Bengali Meaning: দোষী। 

Source: Merriam-Webster Dictionary, Accessible Dictionary by Bangla Acedemy.