Inferior cow? (5)
I believe the answer is:
lower
I believe this is a double definition.
'inferior' is the first definition.
(similar in meaning)
'cow?' is the second definition.
(an animal which moos or lows)
(Other definitions for lower that I've seen before include "where are trousers in relation?" , "Cow" , "Let down using rowel" , "of lesser status" , "Let down, being inferior" .)