No energy inspires pit candidate (7)
I believe the answer is:
nominee
'candidate' is the definition.
(synonyms)
'no energy inspires pit' is the wordplay.
'energy' becomes 'e' (physics symbol as in E=mc2).
'inspires' indicates putting letters inside (inspire means to breathe in).
'pit' becomes 'mine' (I've seen this before).
'no'+'e'='noe'
'noe' enclosing 'mine' is 'NOMINEE'.
(Other definitions for nominee that I've seen before include "Candidate for office" , "Candidate - appointed person" , "His/her name is put forward" , "One put up for office" , "somebody put up" .)