Keep a rat to produce a parrot (8)
I believe the answer is:
parakeet
'a parrot' is the definition.
(parakeet is a kind of parrot)
'keep a rat to produce' is the wordplay.
'to produce' indicates anagramming the letters.
'keep'+'a'+'rat'='keeparat'
'keeparat' anagrammed gives 'PARAKEET'.
(Other definitions for parakeet that I've seen before include "Small long-tailed parrot" , "Brightly-coloured African bird" , "Flier" , "Tropical bird" , "Colourful singer" .)