Head for A Nightmare on Elm (5)
I believe the answer is:
melon
'head' is the definition.
The answer and definition can be both plants as well as being singular nouns.
Maybe you can see a link between them that I don't see?
'a nightmare on elm' is the wordplay.
'on elm' can be anagrammed to 'MELON'.
Though, I am not sure how this is indicated.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for melon that I've seen before include "Large vine fruit" , "Ogen or cantaloupe, for instance" , "Member of the gourd family" , "Eg, cantaloupe, galia" , "Type of pepo" .)