Gabby, garrulous (7)
I believe the answer is:
voluble
I believe this is a double definition.
'gabby' is the first definition.
(similar in meaning)
'garrulous' is the second definition.
(similar in meaning)
(Other definitions for voluble that I've seen before include "Given to talking a lot" , "Talkative" , "With plenty to say" , "Loquacious" , "Gabby, garrulous" .)