Mysterious holy man buzzed with energy (7)
I believe the answer is:
strange
'mysterious' is the definition.
(thesaurus)
'holy man buzzed with energy' is the wordplay.
'holy man' becomes 'st'.
'buzzed' becomes 'rang' (both can mean telephoned).
'with' is a charade indicator (letters next to each other).
'energy' becomes 'e' (physics symbol as in E=mc2).
'st'+'rang'+'e'='STRANGE'
(Other definitions for strange that I've seen before include "Odd, alien" , "Out of the ordinary" , "Odd or unfamiliar" , "as quarks in certain hadrons" , "Odd - rum" .)