Stop using TV as a diversion (5)
I believe the answer is:
avast
'stop' is the definition.
(I've seen this before)
'tv as a diversion' is the wordplay.
'diversion' indicates an anagram.
'tv'+'as'+'a'='tvasa'
'tvasa' anagrammed gives 'AVAST'.
'using' acts as a link.
(Other definitions for avast that I've seen before include "shout stopping the ship" , "order for tar" , "Stop on board" , "Stop (nautical)" , "Stop sailing" .)