Month a boxer initially talked about a liquid measure (9)
I believe the answer is:
decalitre
'a liquid measure' is the definition.
'decalitre' can be an answer for 'measure' (decalitre is a kind of measure). I'm not sure about the 'a liquid' bit.
'month a boxer initially talked' is the wordplay.
'month' becomes 'dec' (abbreviation for December).
'a boxer' becomes 'Ali' (Muhammad Ali).
'initially' says to put letters next to each other (some letters go before others).
'talked' becomes 'tre' (I can't explain this - if you can you should give a lot more credence to this answer).
'dec'+'ali'+'tre'='DECALITRE'
'about' acts as a link.
Can you help me to learn more?
(Other definitions for decalitre that I've seen before include "Quantity of liquid" , "several pints" .)