Bitter variety of melon (5)
I believe the answer is:
lemon
'bitter variety' is the definition.
The definition and answer can be both human attributes as well as being singular nouns.
Maybe there's an association between them I don't understand?
'of melon' is the wordplay.
'of' indicates anagramming the letters (the answer comes from or 'of' the letters).
'melon' anagrammed gives 'LEMON'.
Can you help me to learn more?
(Other definitions for lemon that I've seen before include "Dab" , "Fruit-tree" , "Citrus fruit (is it the answer?)" , "Useless object" , "Washout" .)