Trigram

Part of speech: noun

Definitions

1. A set of three letters or other units that appear one after another in a text or sequence ; one of the eight symbols of three stacked solid or broken lines used in the I Ching
2. Three consecutive characters or items taken together as a unit for analysis ; a symbol made of three horizontal lines, each either whole or broken, from the Chinese Book of Changes
3. A run of three adjacent letters, sounds, or elements studied in linguistics and text analysis ; any of the eight three-line figures used in Chinese divination and philosophy

Etymology: "Trigram" packs two Greek building blocks into one three-letter unit. Its second half, "-gram," comes from Ancient Greek "grámma," meaning "letter" or "mark," which itself grew from "gráphō," "to write" or "to scratch." The Greek word for a written mark was thus rooted in the act of scratching a surface. The first half, "tri-," is the familiar Greek and Latin prefix meaning "three." Put together, the literal sense is "three marks," and the word is a plain technical formation: the "-gram" element appears across English in words like "telegram" and "diagram," where it means something written or drawn. A trigram is therefore simply a three-letter written unit, and the compound's meaning follows directly from its parts.