Greek king, insignificant person, almost a hero (9)
I believe the answer is:
pygmalion
'greek king' is the definition.
'pygmalion' can be an answer for 'king' (I have seen 'Ancient king' mean 'pygmalion' so perhaps 'king' could also mean 'pygmalion'). I'm not sure about the 'greek' bit.
'insignificant person almost a hero' is the wordplay.
I cannot quite see how this works, but
'person' could be 'lion' (lion is a kind of person) and 'lion' is located in the answer.
'a' is within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for pygmalion that I've seen before include "work of an Irishman" , "Legendary king of Cyprus - Shaw play" , "His sculpture came to life" , "The Greek king who created a statue of a woman and fell in love with it" , "Ancient king" .)