Watch Pete cast off (8)
I believe the answer is:
spectate
'watch' is the definition.
(I know that spectate is a more specific form of the action the watch)
'pete cast off' is the wordplay.
'off' indicates anagramming the letters.
'pete'+'cast'='petecast'
'petecast' is an anagram of 'SPECTATE'.
(Other definitions for spectate that I've seen before include "Be an onlooker" , "Look on (at a match)" , "Watch (at sports event)" , "Watch (eg, a game)" , "Perhaps enjoy sport" .)