Like some big game one bungled in series (7)
I believe the answer is:
leonine
'like some big game' is the definition.
(like lions)
'one bungled in series' is the wordplay.
'bungled' is an anagram indicator.
'in' indicates putting letters inside.
'series' becomes 'line' (line is a kind of series).
'one' is an anagram of 'eon'.
'eon' inserted within 'line' is 'LEONINE'.
(Other definitions for leonine that I've seen before include "Like a wild animal" , "Relating to a carnivore or to certain popes" , "Like the king of the jungle" , "verse" , "Characteristic of a lion" .)