Talk fast, like a person needling you? (6)
I believe the answer is:
jabber
'talk' is the definition.
(jabbering is a kind of talking)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for jabber that I've seen before include "One possibly taking a poke" , "Talk rapidly with little sense" , "indistinct speech" , "Talk incessantly" , "Indistinct talk" .)