Decency (7)
I believe the answer is:
modesty
'decency' is the definition.
(I know that modesty is a type of decency)
This is the entire clue.
(Other definitions for modesty that I've seen before include "Unassuming character" , "Unpretentious style" , "Quality of being unpretentious" , "Diffidence" , "Unassumingness" .)