One man's name for Diana (4)

I believe the answer is:

ross

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

'one man's' is the definition.

'name for diana' is the wordplay.
'name' becomes 'Ros'.
'for diana' becomes 's' (I am not sure about this - if you are sure you should believe this answer much more).
'ros'+'s'='ROSS'

Can you help me to learn more?

(Other definitions for ross that I've seen before include "Wye town; Antarctic sea" , "- and Cromarty, former Scottish county" , "Macbeth nobleman; Antarctic sea" , "Macbeth thane; a T. E. Lawrence pseudonym" , "Diana --, Motown singer" .)

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.