Rabbit, something for breakfast (6)
I believe the answer is:
waffle
I believe this is a double definition.
'rabbit' is the first definition.
(both can mean to talk excessively)
'something for breakfast' is the second definition.
(I've seen this before)
(Other definitions for waffle that I've seen before include "Battered cake" , "crisp golden pancake" , "Talk vaguely and at length" , "Hot air" , "Cake with grid-like surface" .)