Hank got out of shoemaking operation due to over-concern for own well-being (6)
I believe the answer is:
egoism
'hank' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for egoism that I've seen before include "Exaggerated sense of one's own importance" , "Self-seeking" , "sense of superiority" , "Self-centredness, vanity" , "Excessive self-regard" .)