Extravagant version of true love (5)
I believe the answer is:
outre
'extravagant' is the definition.
(outre can mean extravagant or eccentric)
'version of true love' is the wordplay.
'version of' indicates an anagram.
'love' becomes 'o' (love means zero in tennis).
'true'+'o'='trueo'
'trueo' with letters rearranged gives 'OUTRE'.
(Other definitions for outre that I've seen before include "flaky" , "Peculiar" , "Extravagant - fantastic" , "Somewhat unusual" , "Off the wall" .)