Optimistically expecting hard work and energy (4)
I believe the answer is:
hope
'optimistically expecting' is the definition.
I can't judge whether this defines the answer.
'hard work and energy' is the wordplay.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'work' becomes 'op' (abbreviation for opus).
'and' is a charade indicator (letters next to each other).
'energy' becomes 'e' (physics symbol as in E=mc2).
'h'+'op'+'e'='HOPE'
Can you help me to learn more?
(Other definitions for hope that I've seen before include "Positive expectation" , "confidence" , "writer" , "Trustful expectation" , "English novelist" .)