Crossword Genius

Tribes getting energy, and more energy, free (7)

Ross

I believe the answer is:

cleanse

I'm a little stuck... Click here to teach me more about this clue!

'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" .)

I've seen this clue in The Daily Express.
Want a hint initially instead of a full solution? Install my app