Early moves to screen commercial earlier (7)
I believe the answer is:
already
'earlier' is the definition.
(thesaurus)
'early moves to screen commercial' is the wordplay.
'moves' indicates an anagram.
'to screen' is an insertion indicator.
'commercial' becomes 'ad' (abbreviation for advertisement).
'early' is an anagram of 'alrey'.
'alrey' enclosing 'ad' is 'ALREADY'.
(Other definitions for already that I've seen before include "earlier than might have been expected" , "Indication of impatience (US)" , "Previously" , "Even this soon" , "By the time in question" .)