Speak of making love for payment (5)
I believe the answer is:
orate
'speak of' is the definition.
'orate' can be an answer for 'speak' (orating is a kind of speaking). I am unsure of the 'of' bit.
'love for payment' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'for payment' becomes 'rate' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'o'+'rate'='ORATE'
'making' is the link.
Can you help me to learn more?
(Other definitions for orate that I've seen before include "Give speech" , "Speak in public" , "Declaim or rant" , "Speak pompously and at length" , "Speechify" .)