meaning - 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.