Word Origin & History
1853, of uncertain origin, probably related to spiff "well-dressed man." Spiffing "excellent" was very popular in 1870s slang. Uncertain relationship to spiff (n.) "percentage allowed by drapers to their young men when they effect sale of old fashioned or undesirable stock" (1859), or to spiflicate "confound,
overcome completely," a cant word from 1749 preserved in Amer.Eng. slang spiflicated "drunk," first recorded 1906 in O.Henry.