Green-fingered fellow cultivated runners, keeping May free (10)
I believe the answer is:
nurseryman
'green-fingered fellow' is the definition.
The definition and answer can be both people as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'cultivated runners keeping may free' is the wordplay.
'cultivated' is an anagram indicator.
'keeping' means one lot of letters goes inside another (some letters kept inside).
'free' is an anagram indicator.
'runners' anagrammed gives 'nursern'.
'may' with letters rearranged gives 'yma'.
'nursern' placed around 'yma' is 'NURSERYMAN'.
Can you help me to learn more?
(Other definitions for nurseryman that I've seen before include "Worker rearing plants" , "Plant grower and seller" , "Horticulturist" , "fellow whose charges are small?" , "One who grows plants" .)