Outside left in a fine score, tumbling (8)
I believe the answer is:
alfresco
'outside' is the definition.
(I've seen this before)
'left in a fine score tumbling' is the wordplay.
'left in' becomes 'al' (I've seen this in other clues).
'a fine' becomes 'f' (abbreviation).
'tumbling' indicates an anagram.
'score' is an anagram of 'resco'.
'al'+'f'+'resco'='ALFRESCO'
(Other definitions for alfresco that I've seen before include "out of the house" , "In the open air" , "Outdoors, meal perhaps" , "Open-air" , "exposed to the fresh air" .)