Optimistically expecting hard work and energy (4)
I believe the answer is:
hope
'optimistically expecting' is the definition.
I can't judge whether this definition defines the answer.
'hard work and energy' is the wordplay.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'work' becomes 'op' (short for opus).
'and' means one lot of letters go next to another.
'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" .)