Quite commonly, the Oxford English Dictionary (OED) doesn’t know the origins of words, although they speculate whenever they can if no verifiable history is present. They believe that goluptious is either arbitrarily formed as a humorous slang word or perhaps was a corruption of the word voluptuous (which has a similar meaning of being delightful to the senses).
The earliest use of goluptious noted by the OED comes from Scottish writer John Strang, in his 1856 book Glasgow and Its Clubs: Or Glimpses of the Condition, Manners, Characters, and Oddities of the City, During the Past and Present Century. In a passage describing a music venue called The Packers’ Club, he uses the word, spelled galoptious:
If two spellings aren’t enough, there’s a third mentioned by the OED — galopshus — as well as others mentioned online, such as galuptious. But, no matter how it’s spelled, the word always indicates that something is delightful, splendid, grand, etc.
A bit of a tangent here but, poking around further, I came across an absolutely goluptious listing of adjectives similar to (and including) our word today. There are too many goluptious entries not to share them all (and why not, as it’s a public domain book at this point). Here are a few pages from the 1917 book Dialect Notes, a publication of the American Dialect Society (which still exists!):
Wow, who knew Nebraskans were such colorful wordsmiths. Luperglobsloptious? That’s the best word ever!
✍🏻 Jim Dee maintains three blogs — Hawthorne Crow, Web Designer | Web Developer Magazine, and Wonderful Words, Defined — and contributes to various Medium pubs. Connect at JPDbooks.com, Amazon, FB, Twitter, Instagram, LinkedIn, Medium, or Jim [at] ArrayWebDevelopment.com. His latest screwball literary novel, CHROO, is a guaranteed good time.