A word about Max (3)
I believe the answer is:
mad
'a word about max' is the definition.
I can't tell whether this definition defines the answer.
'a word about' is the wordplay.
'word' becomes 'md' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'about' indicates putting letters inside.
'a' inserted into 'md' is 'MAD'.
Can you help me to learn more?
(Other definitions for mad that I've seen before include "Extremely foolish" , "Berserk" , "lunatic" , "Frantic" , "Roused to anger" .)