Pole rode, lacking energy (3)
I believe the answer is:
rod
'pole' is the definition.
(synonyms)
'rode lacking energy' is the wordplay.
'lacking' is a deletion indicator.
'energy' becomes 'e' (physics symbol as in E=mc2).
'rode' with 'e' removed is 'ROD'.
(Other definitions for rod that I've seen before include "- - , pole or perch" , "Fishing pole" , "Fisherman's item" , "Wand - fishing stick" , "16.5 feet" .)