Shorten, expurgate (7)
I believe the answer is:
abridge
I believe this is a double definition.
'shorten' is the first definition.
(synonyms)
'expurgate' is the second definition.
(thesaurus)
(Other definitions for abridge that I've seen before include "Concentrate" , "Big read (anag) - shorten text" , "Make a precis of" , "trim" , "Make short work" .)