Assume he's from London (3)

I believe the answer is:

don

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

'assume' is the definition.
(I know that assume can be written as don)

'he's from london' is the wordplay.
'DON' is hidden within the letters.
However, I'm uncertain how this is indicated.

Can you help me to learn more?

(Other definitions for don that I've seen before include "Put on clothes like noss" , "Put on the learned man" , "University teacher" , "Professor" , "Put on; college teacher" .)

I've seen this clue in the Evening Standard.

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.