Cast Pete in play and watch (8)
I believe the answer is:
spectate
'watch' is the definition.
(spectating is a kind of watching)
'cast pete in play' is the wordplay.
'in play' is an anagram indicator.
'cast'+'pete'='castpete'
'castpete' with letters rearranged gives 'SPECTATE'.
'and' acts as a link.
(Other definitions for spectate that I've seen before include "View" , "Be an onlooker" , "Watch (eg, a game)" , "Look on (at a match)" , "Watch (a game, etc)" .)