Rabbit on jet (5)
I believe the answer is:
spout
I believe this is a double definition.
'rabbit on' is the first definition.
(synonyms)
'jet' is the second definition.
(I've seen this in another clue)
(Other definitions for spout that I've seen before include "Talk (rubbish); part of pot" , "Hold forth at length" , "rant" , "Make speech; part of teapot" , "Talk at length; part of kettle" .)