Chattering (9)

I think it could be either:

gibbering

prattling

'chattering' is the definition.
('gibber' can be a synonym of 'chatter')

This is all the clue.

(Other definitions for gibbering that I've seen before include "Raving" , "Prattling" , "Blathering" .)

I've seen this clue in the Evening Standard and the Sydney Morning Herald.

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.