Caught burrowing animal, heading off for fight (6)
I believe the answer is:
combat
'for fight' is the definition.
(synonyms)
'caught burrowing animal heading off' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'burrowing animal' becomes 'wombat' (I've seen this before).
'heading off' means to remove the first letter.
'wombat' with its first letter removed is 'ombat'.
'c'+'ombat'='COMBAT'
(Other definitions for combat that I've seen before include "Fight or contest, may be mortal" , "Fight against; fighting" , "Conflict" , "Battle, warfare" , "Oppose" .)