In an earlier age, a noted artist (3)
I believe the answer is:
era
'noted artist' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'in an earlier age a' is the wordplay.
'in' says the answer is hidden in the clue.
'ERA' is hidden within 'earlier age a'.
Can you help me to learn more?
(Other definitions for era that I've seen before include "Long stretch" , "Important time" , "Aeon" , "Significant time" , "Are involved in time span" .)