Crossword Genius

A master of many subjects (5)

Ross

I believe the answer is:

ruler

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

'a master' is the definition.
(thesaurus)

I don't understand the rest of the clue.

Can you help me to learn more?

(Other definitions for ruler that I've seen before include "King, president etc." , "Commander" , "King or, president, say" , "Emperor - measure" , "Measuring rod; governor" .)

I've seen this clue in The Globe and Mail.
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.