Arbitrary execution of nationalist in Polish city (5)

I believe the answer is:

radom

I'm a little stuck... Click here to teach me more about this clue!

But I can't explain it at all! Could you help me understand?

I've seen this clue in The Hindu.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.