Lawyer thrashed on treaty (8)

I believe the answer is:

attorney

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

'lawyer' is the definition.
(I know that lawyer can be written as attorney)

'thrashed on treaty' is the wordplay.
'on treaty' can be anagrammed to 'ATTORNEY'.
But, I am unsure how the anagram is indicated.

Can you help me to learn more?

(Other definitions for attorney that I've seen before include "Any torte (anag.)" , "No treaty (anag.)" , "US lawyer" , "An American lawyer or barrister" , "brief" .)

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.