On Google NGrams, I actually triangulated the use of the word “funk” back to 1638, to a book by Sir Thomas Herbert called Some Yeares Traveled into Divers Parts of Asia and Afrique, almost in Medieval English, and with two really long subtitles. It seems to be a word related to shipping and seafaring. From page 117: “They funk the vice and rear admiral of [someone’s] fleet; by that utterly losing their late hopes of marine command and excellence.”

Perhaps that relates to the future of funk or funkiness. To get a better idea, I also searched “funky” in Ngrams. I came up with a hit from 1839, a section of a novel called Ten Thousand A-Year published in  The Museum of Foreign Literature, Science and Art. (Novels being produced serially back then.): “I feel all of a sudden uncommon funky — I think that last cigar of yours wasn’t –” On further research, this Samuel Warren novel was apparently  wildly popular in the 1850s; it features such characters as Mr. Pimp Yahoo and Mr. Going Gone.
So here a state of being “off,” maybe sick, makes an appearance in funk’s vernacular history. As in “a funk.” This is widely used by the 1890s.

In the 1930s – 1940s Funky sees a surge in its usage. It becomes a state of fright, nervousness or timidity, according to 1940’s Modern Language Notes.
“It was Harold who was funky of the cows” from 1930’s April Fools: A Comedy of Bad Manners.

There’s a real musical reference in 1939, from Frederick Ramsey’s Jazzmen. “The words of the song, which later became his ‘theme’ song, went: I thought I heard Buddy Bolden say, ‘Funky-butt, funky-butt, take it away.'”

Through funky butt, the connection of funk to music starts to coalesce. In Queen New Orleans, it is referenced as a club or venue where a “small, bulkily built boy listened nightly to the silver magic of Buddy’s notes. No one paid attention to him then. He was a young Louis Armstrong” Which suggests that the term funky was connected to music for quite some time before it started being used widely as such in the 1950s.

(Later in a 1958 issue of Life Mag: “Funky Butt Hall, that place was wild, and they all kinds of coon shouters””

Funky butt is also a song referenced in a 1950 issue of Jazz Music, in an article by Max Jones. It was “A kind of popular tune. . . A standard blues with more solos than this group [The Mezzrow-Bechet Quintet] usually features.”

In the late fifties, many music publications start to examine the qualities of “funk” or “funky” music