Crossword Genius

Anti-communist union lacks a Republican firmness (8)

Ross

I believe the answer is:

solidity

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

'firmness' is the definition.
(I've seen this before)

I don't understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for solidity that I've seen before include "Firmness" , "Substance" , "Firm quality" .)

I've seen this clue in The Times.
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.