One who contradicts a measure? (6)

I believe the answer is:

denier

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

'measure?' is the definition.
(I have seen 'fine measure' mean 'denier' so perhaps 'measure' could also mean 'denier')

I don't understand the rest of the clue.

Can you help me to learn more?

(Other definitions for denier that I've seen before include "One who doesn't believe" , "old coin" , "Peter?" , "One refusing to admit" , "One refuses to acknowledge" .)

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.