Here are some possible explanations:
* Possible connection to "spiff": One theory suggests "spiffy" evolved from the slang word "spiff," which meant "a tip or bonus," and later expanded to encompass a sense of being "stylish" or "smart."
* Possible connection to "spifflicated": Another theory connects "spiffy" to the slang term "spifflicated," meaning "drunk" or "intoxicated." This connection might hint at a sense of exhilaration or excitement associated with the word.
* Possible onomatopoeia: Some suggest "spiffy" might be a playful onomatopoeia, capturing the sound of something "snappy" or "sharp."
* Possible influence of "spick and span": The phrase "spick and span" meaning "spotlessly clean" might have contributed to the association of "spiffy" with a sense of neatness and tidiness.
Ultimately, the precise origin of "spiffy" remains uncertain. Regardless of its exact root, the word became popular during the 1930s and 1940s, and its meaning has evolved over time to encompass a sense of stylishness, attractiveness, or excellence.