Said about Charlie: 'E's a know-all (6)
I believe the answer is:
oracle
'a know-all' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'said about charlie 'e's' is the wordplay.
'said' becomes 'oral' (both can mean spoken).
'about' means one lot of letters goes inside another.
'charlie' becomes 'C' (phonetic alphabet: alpha, bravo, charlie etc.).
'oral' going around 'c' is 'oracl'.
'oracl'+'e'='ORACLE'
Can you help me to learn more?
(Other definitions for oracle that I've seen before include "One successfully worked" , "ambiguous message" , "Voice of god" , "Authoritative person who divines the future" , "Source of divine prophesy" .)