What part of speech is the word "entire" in "over the little garden field entire"?

The sentence is: "After a while she got up from where she was and went over the little garden field entire."

A quote from Their Eyes Were Watching God by Zora Neale Hurston.

I want to know if the word "entire" is a flat adverb, a postpositive adjective, a noun alternative for entirety, or some other part of speech in the bolded sentence above.

Thank you for reading. I hope you will respond and share your thoughts with me.

It's a postpositive adjective, poetically reversed from its noun. It's essentially the same as:

the entire garden field

There's nothing else entire could really be modifying here.

The collision with little makes it awkward in its normal position (the entire, little garden field), since it's such a different function from the other adjective. One is describing the field itself while the other is qualifying the portion of the field walked over.

In the UK, it shows up a lot in poetry: swapping the noun and adjective can give a nice flavour, and it can help with rhyming. Something like:

He stood atop the grasses green

And sometimes you run into funny constructions like St. Michaels Without or the demon within.

To Save the World Entire.