Obtained energy before first self-seeker (7)
I believe the answer is:
egotist
'self-seeker' is the definition.
(thesaurus)
'obtained energy before first' is the wordplay.
I cannot quite understand how this works, but
'obtained' could be 'got' ('get' can be a synonym of 'obtain') and 'got' is located in the answer.
'energy' could be 'e' (physics symbol as in E=mc2) and 'e' is present in the answer.
'first' could be 'ist' (ist resembles 1st) and 'ist' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for egotist that I've seen before include "Excessively conceited person" , "One excessively conceited" , "Bighead" , "A self-absorbed and conceited person" , "Self-interested person" .)