cap-a-pie

Think of a medieval knight riding off to battle completely encased (from head to foot, as it were) in armor. Knights thus outfitted were said to be "armed cap-a-pie." The term cap-a-pie (or cap-à-pie), which has been used in English since at least the 16th century, descends from the Middle French phrase de cap a pé, meaning "from head to foot." Nowadays, it is generally extended to more figurative armor, as in "armed cap-a-pie against criticism." Cap-a-pie has also been credited with parenting another English phrase. Some people think the expression "apple-pie order," meaning "perfect order," may have originated as a corruption of "cap-a-pie order." The evidence for that theory is far from orderly, however, and it must be regarded as speculative.