Also known as a palindrome (3)
I believe the answer is:
aka
'also known as' is the definition.
(synonyms)
'a palindrome' is the wordplay.
'palindrome' becomes 'ka' (I can't justify this - if you can you should believe this answer much more).
'a'+'ka'='AKA'
Can you help me to learn more?
(Other definitions for aka that I've seen before include "Also known as, initially" , "Also called (abbrev.)" , "Using the byline" , "Notation indicating alias or other name" , "Notation with initials indicating alternative name" .)