Setter's mature public front (5)
I believe the answer is:
image
'public front' is the definition.
'image' can be an answer for 'front' (thesaurus). I am not sure about the 'public' bit.
'setter's mature' is the wordplay.
'setter's' becomes 'I'm' (referring to the crossword setter).
'mature' becomes 'age' (synonyms).
'im'+'age'='IMAGE'
Can you help me to learn more?
(Other definitions for image that I've seen before include "Visual or mental representation" , "Likeness, could be spitting" , "External impression" , "Picture (involving one letter change from 10)" , "Likeness U symbol" .)