n. A poem in which the length of each word corresponds to a digit in the decimal expansion of the mathematical constant pi.
2011
If calculating decimal places isn’t your idea of fun, you can always memorize them. The current unofficial world record belongs to Japan’s Akira Haraguchi, who rattled off 100,000 decimal places in 2006. People who need help remembering digits often fall back on memorizing a "piem," a poem in which the number of letters in each word corresponds to pi’s digits.
2011
People have devised any number of methods to help them remember well more than ten digits. There is a form of poetry known as a piem, in which pi’s digits are represented by the number of letters in each word. The best-known piem renders the first fifteen digits of pi as "How I want a drink, alcoholic of course, after the heavy chapters involving quantum mechanics."
2006 (earliest)
There are lots of ways to remember pi, including things called piems, poems where the length of each word represents a digit.
I post this term in honor of Pi Day, which occurs every March 14. What's so special about that date? In countries that use the m/dd date format, March 14 is 3/14, and the decimal expansion of Pi begins with 3.14. Easy as, well, Pi.