Pet belonging to us feeds at five, roughly (9)
I believe the answer is:
favourite
'pet' is the definition.
(I know that pet can be written as favourite)
'belonging to us feeds at five roughly' is the wordplay.
'belonging to us' becomes 'our' (us, you and me).
'feeds' means one lot of letters goes inside another (one word is fed by another set of letters).
'roughly' indicates an anagram.
'at'+'five'='atfive'
'atfive' anagrammed gives 'favite'.
'our' put inside 'favite' is 'FAVOURITE'.
(Other definitions for favourite that I've seen before include "that attracts lots of money" , "competitor thought likely to win" , "Beloved pet" , "Sir Walter Raleigh was one" , "Most liked" .)