Energy of half a dozen maidens (3)
I believe the answer is:
vim
'energy' is the definition.
('vim' can be a synonym of 'energy')
'half a dozen maidens' is the wordplay.
'half a dozen' becomes 'vi' ('vi' can be a synonym of 'half a dozen').
'maidens' becomes 'm' (cricket abbreviation).
'vi'+'m'='VIM'
'of' is the link.
(Other definitions for vim that I've seen before include "Exuberant vigour" , "Energy, enthusiasm" , "Pep (informal)" , "Informal energy or drive" , "Pep and vigour" .)