Tribes getting energy, and more energy, free (7)
I believe the answer is:
cleanse
'free' is the definition.
(thesaurus)
'tribes getting energy and more energy' is the wordplay.
'tribes' becomes 'clans' ('clan' can be a synonym of 'tribe').
'getting' is an insertion indicator.
'energy' becomes 'e' (physics symbol as in E=mc2).
'and' is a charade indicator (letters next to each other).
'more energy' becomes 'e' (physics symbol as in E=mc2. I am not sure about the 'more' bit.).
'clans' enclosing 'e' is 'cleans'.
'cleans'+'e'='CLEANSE'
Can you help me to learn more?
(Other definitions for cleanse that I've seen before include "carry out purification" , "Make pure" , "Disinfect" , "absolve from sin" , "Scrub" .)