Love neat last letter (5)
I believe the answer is:
omega
'last letter' is the definition.
(last letter of the Greek alphabet)
'love neat' is the wordplay.
'love' becomes 'o' (love means zero in tennis).
'neat' becomes 'mega' (I am not sure about this - if you are sure you should believe this answer much more).
'o'+'mega'='OMEGA'
Can you help me to learn more?
(Other definitions for omega that I've seen before include "The last in a series of letters" , "long letter" , "Athenian character" , "16 letter" , "Last letter of the Greek alphabet" .)