Agreed to lose a selfish characteristic (5)
I believe the answer is:
greed
'selfish characteristic' is the definition.
The definition and answer can be both human attributes as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'agreed to lose a' is the wordplay.
'to lose' indicates named letters should be taken away.
'agreed' with 'a' taken away is 'GREED'.
Can you help me to learn more?
(Other definitions for greed that I've seen before include "Circuit" , "Selfish desire" , "Gluttony" , "sin" , "selfish habit" .)