Team acts badly protecting single champ (9)
I believe the answer is:
masticate
'champ' is the definition.
(thesaurus)
'team acts badly protecting single' is the wordplay.
'badly' indicates anagramming the letters.
'protecting' is an insertion indicator.
'single' becomes 'i' (one).
'team'+'acts'='teamacts'
'teamacts' with letters rearranged gives 'mastcate'.
'mastcate' going around 'i' is 'MASTICATE'.
(Other definitions for masticate that I've seen before include "champ" , "Crush" , "Chomp" , "deal with mouthful" , "Process food" .)