Sad mean-spirited mate left -- fired (8)
I believe the answer is:
inspired
'fired' is the definition.
(thesaurus)
'sad mean-spirited mate left' is the wordplay.
'sad' is an anagram indicator.
'left' suggests deleting specific letters.
'mean'+'spirited'='meanspirited'
'meanspirited' with 'mate' taken out is 'nspiried'.
'nspiried' with letters rearranged gives 'INSPIRED'.
(Other definitions for inspired that I've seen before include "Gave enthusiasm to" , "Filled with the urge to do something creative" , "Stirred to action, fired up" , "Enthused" , "prompted" .)