Crossword Genius

Rev initially gracious with peacekeepers (3)

Ross

I believe the answer is:

gun

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

Here is my best explanation:

'rev' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.

'initially gracious with peacekeepers' is the wordplay.
'initially' suggests taking the first letters.
'with' says to put letters next to each other.
'peacekeepers' becomes 'un'.
The initial letter of 'gracious' is 'g'.
'g'+'un'='GUN'

Can you help me to learn more?

This clue was last seen in The Independent