Cyclopaedias

Part of speech: noun

Definitions

1. A comprehensive reference work that encompasses a wide range of information arranged alphabetically or thematically
2. A collection of articles and entries covering various subjects for knowledge and research purposes
3. An extensive resource compiling factual details, often illustrated, designed for broad educational use

Etymology: "Cyclopaedias" is the plural of "cyclopaedia", a large reference book, and the word's real surprise is that it is essentially a variant of "encyclopaedia" built on the same Greek ideas. Its first element comes from Greek "kúklos", meaning "circle", and its second from "paideía", meaning "child-rearing" or "education". Put together, the idea is a circle of learning: knowledge rounded up in one place, covering the whole cycle of a subject. The "cyc-" spelling is the older, more literal form, and "encyclopaedia" adds the prefix "en-", meaning "in", to give the sense of learning contained within a circle. Both words carry the same underlying image of all knowledge gathered into a single round. The plural simply follows the regular English pattern of adding "-s" to a noun ending in "-a".