Lickety-split means at once, right away, immediately. Lickety-split is an American phrase, probably derived from going at quite a lick and other similar phrases. The lick in this case, most probably refers to the practice of hurrying animals along with a lick from a whip. The word lickety-split appears in America in the 1850s. According to Google’s Ngram, the term lickety-split peaked in popularity in the 1940s, dipped through the sixties, and is today nearly as popular as it was seventy years ago. Note that lickety-split is properly spelled with a hyphen, though one does see it rendered as two words, unhyphenated.
Examples
The lickety-split pacing, cheerfully impudent tone and breezy allusiveness may put some audience members in mind of such Reduced Shakespeare productions as “The Complete History of America (Abridged)” and “The Bible: The Complete Word of God (Abridged).” (The Washington Post)
My mother, who’s never even heard of the seed, gobbled it up lickety split before dinner, I might add. (The Loveland Reporter-Herald)
Though I wasn’t really expecting Jon Snow to be resurrected in this episode—he’s too big a plot point to kill and unkill lickety-split—it was nice to see him again, dead though he is, lying in that pile of ice blood. (The New Yorker)
Though famous for lickety-split wordplay, Khalif Diouf, aka Le1f (pronounced “leaf”) makes quite an impression before he even opens his mouth. (The Guardian)
Rainey Woodward and Hannah Davidson teamed up to break the 23 year old meet record in the two-person mile at the annual Lakeland Relays on Tuesday at Corbit Field, clocking a lickety-split 4:34 in the pair of 800s. (The Bonner County Daily Bee)