Cancelled in full, sadly, by current newspaper boss (9)
I believe the answer is:
nullified
'cancelled' is the definition.
(nullifying is a kind of cancelling)
'in full sadly by current newspaper boss' is the wordplay.
'sadly' is an anagram indicator.
'by' means one lot of letters go next to another.
'current' becomes 'I' (symbol for electric current).
'newspaper boss' becomes 'ed' (short for editor).
'in'+'full'='infull'
'infull' with letters rearranged gives 'nullif'.
'nullif'+'i'+'ed'='NULLIFIED'
(Other definitions for nullified that I've seen before include "Cancelled out" , "Made invalid" , "Abrogated" , "revoked" , "Scrubbed" .)