Entered record horse with energy in old racing (6)
I believe the answer is:
logged
'entered' is the definition.
(logging is a kind of entering)
'record horse with energy in old racing' is the wordplay.
'record horse' becomes 'gg' (I am not sure about the 'record' bit.**).
'with' says to put letters next to each other.
'energy' becomes 'e' (physics symbol as in E=mcg).
'in' means one lot of letters goes inside another.
'racing' indicates anagramming the letters (to race around can mean to move).
'gg'+'e'='gge'
'old' is an anagram of 'lod'.
'gge' placed into 'lod' is 'LOGGED'.
Can you help me to learn more?
(Other definitions for logged that I've seen before include "Entered in ship's diary" , "felled" , "Recorded" .)