Prattle on (3)
I believe the answer is:
gab
'prattle on' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for gab that I've seen before include "Talk at length, chatter" , "The gift of the . . . is ability to talk fluently" , "rabbit" , "The gift of the - means verbal fluency" , "gossip" .)