Hypergeometric

Part of speech: adjective

Definitions

1. Relating to a special mathematical function defined by a series ; describing a probability distribution that counts successes when drawing without replacement from a finite population
2. Concerning a particular infinite series of a specific form used in advanced mathematics ; involving a probability model for sampling without replacement from a finite group
3. Pertaining to a special function expressed as a power series ; characterizing the statistical pattern of draws taken from a limited set without returning items

Etymology: Hypergeometric is a plain compound: "hyper-", from Ancient Greek "hupér" meaning "over" or "beyond", joined to "geometric". Its sense is therefore "beyond the ordinary geometric," which fits the term's use in mathematics for a family of special functions and series that generalise the basic geometric series. The word's history is not a story of meaning drift. The prefix kept its original sense of excess or extension, and "geometric" retained its link to measurement and shape. Mathematicians combined the two to name functions that extend what geometric series can do, rather than inventing an unrelated label.