Apple-pie order is an idiom with an uncertain origin. We will examine the meaning of the idiomatic phrase apple-pie order, where it came from, and some examples of its use in sentences.
Apple-pie order means neat and tidy, everything in order, all things in their place. Synonyms for apple-pie order that may be found in a thesaurus are orderly, precise, tidy, systematized, well-kept. The idiom apple-pie order has been in use since the 1700s, but its origin is uncertain. The earliest known use was by Sir Thomas Pasley in his work, Private Sea Journals, from 1780: “Their Persons Clean and in apple-Pie order on Sundays.” Most believe that apple-pie order is a corruption of a French phrase, either nappe-pliée, which means folded napkin, or cap-à-pie, which means head to foot. Note that apple-pie order is properly rendered with one hyphen, though the term apple pie, on its own, does not take a hyphen.
My personal take on apple-pie order is that it is a scheme which primarily values precision and exactness, not at the price of functionality nor as a sacrifice to convenience (though admittedly too much judgement and refinement may spoil that which at first is a delicate thing). (The Millstone News)
All seemed in apple-pie order, for once, and if Wayne Hennessey had not saved brilliantly from Lacazette their capacity for setting themselves riddles would have been sorely tested. (The Guardian)
I left class on Wednesday, my coursework in apple-pie order, looking forward to finishing an assignment and beginning to bake my first layer cake in a loooong while! (The Christian Science Monitor)