Type of wine on billboard is a legendary divine type associated with oak, for one (5)
I believe the answer is:
dryad
'type' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for dryad that I've seen before include "Wood-nymph" , "Nymph of trees" , "Nymph of the woods" , "one stuck in a tree" , "Spirit in the wood" .)