No opposition (3)

I believe the answer is:

yes

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

This might be a double definition.

'no' is the first definition.
(thesaurus)

'opposition' is the second definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.

Can you help me to learn more?

(Other definitions for yes that I've seen before include "Indeed" , "Positive response" , "Word of affirmation" , "Oui" , "That's 27 [RIGHT]" .)

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.