Author is Pound (3)
I believe the answer is:
pen
This clue is a double definition.
'author' is the first definition.
(to pen something is to author it)
'is pound' is the second definition.
(both can mean an animal enclosure)
(Other definitions for pen that I've seen before include "International Association of poets, playwrights etc" , "Shut up" , "Small enclosure" , "'The ... is mightier than the sword'" , "Cage - bird" .)