Lavish times tucking into tuna battered with beer (9)
I believe the answer is:
exuberant
'lavish' is the definition.
(thesaurus)
'times tucking into tuna battered with beer' is the wordplay.
'times' becomes 'x' (2 times 4 is 2 x 4).
'tucking into' indicates putting letters inside.
'battered with' indicates an anagram.
'tuna' with its letters mixed up with 'beer' makes 'euberant'.
'x' placed inside 'euberant' is 'EXUBERANT'.
(Other definitions for exuberant that I've seen before include "Full of high spirits, very lively" , "Enthusiastic" , "High-spirited" , "Abounding in vitality" , "full of glee" .)