Crossword Genius

One leaving departs ancient city ruin (7)

Ross

I believe the answer is:

destroy

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

'ruin' is the definition.
(I know that ruin can be written as destroy)

I don't understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for destroy that I've seen before include "Soundly defeat" , "Wreck" , "Flatten" , "Get rid of" , "Demolish; pull down" .)

I've seen this clue in The Sun.
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.