Specified son with copy from author caught in act (9)
I believe the answer is:
described
'specified' is the definition.
(to specify is to describe in detail)
'son with copy from author caught in act' is the wordplay.
'son' becomes 's' (genealogical abbreviation for son).
'with' says to put letters next to each other.
'copy from author' becomes 'crib' (crib can mean to copy from another author).
'caught in' indicates putting letters inside.
'act' becomes 'deed' (deed is a kind of act).
's'+'crib'='scrib'
'scrib' placed into 'deed' is 'DESCRIBED'.
(Other definitions for described that I've seen before include "Represented in words" , "Portrayed in words" , "Reported" .)