Last listener intended, say, a word of affection (10)
I believe the answer is:
endearment
'a word of affection' is the definition.
(I've seen this before)
'last listener intended say' is the wordplay.
'last' becomes 'end' (I've seen this in another clue).
'listener' becomes 'ear' (body part which hears or listens).
'intended' becomes 'meant' (to mean something is to intend it).
'say' indicates a 'sounds like' (homophone) clue.
'meant' is a homophone of 'ment'.
'end'+'ear'+'ment'='ENDEARMENT'
(Other definitions for endearment that I've seen before include "Fondness" , "Love, affection" , "Affectionate utterance" , "Word of affection" , "Expression of love" .)