All people with energy - even Roy, surprisingly (8)
I believe the answer is:
everyone
'all people' is the definition.
(I've seen this before)
'energy even roy surprisingly' is the wordplay.
'energy' becomes 'e' (physics symbol as in E=mc2).
'surprisingly' indicates an anagram (a surprising ordering of the letters).
'even'+'roy'='evenroy'
'evenroy' with letters rearranged gives 'veryone'.
'e'+'veryone'='EVERYONE'
'with' acts as a link.
(Other definitions for everyone that I've seen before include "Entire group" , "All the people" , "Uncle Tom Cobleigh and all" , "All and sundry" , "All without exception" .)