The same artist's not in Radio Times cutting (5)
I believe the answer is:
ditto
'the same' is the definition.
(thesaurus)
'artist's not in radio times cutting' is the wordplay.
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'not in' suggests deleting specific letters.
'times' becomes 'tt' (two abbreviations for time).
'cutting' indicates putting letters inside (some letters cut their way into a word).
'radio' with 'ra' removed is 'dio'.
'dio' going around 'tt' is 'DITTO'.
(Other definitions for ditto that I've seen before include "As given above" , "Copy" , "Same again, indicated by two dots" , "Notation meaning the same again" , "The same thing" .)