Aromatic, full of energy through this means (6)
I believe the answer is:
hereby
'through this means' is the definition.
('hereby' means using this utterance or statement)
'aromatic full of energy' is the wordplay.
'aromatic' becomes 'herby' (smelling of herbs).
'full of' means one lot of letters goes inside another.
'energy' becomes 'e' (physics symbol as in E=mc2).
'herby' enclosing 'e' is 'HEREBY'.
(Other definitions for hereby that I've seen before include "By this means or act" , "(Formally) with this" , "By means of this, legally speaking" , "By this means, as result of this" , "Not far off" .)