In geometry, an enneagram is a nine-pointed plane figure. It is sometimes called a nonagram.
The Enneagram of Personality, or simply the Enneagram (from the Greek words ἐννέα [ennéa, meaning "nine"] and γράμμα [grámma, meaning something "written" or "drawn"), is a model of the human psyche which is principally understood and taught as a typology of nine interconnected personality types.
The enneagram figure is usually composed of three parts; a circle, an inner triangle (connecting 3-6-9) and an irregular hexagonal "periodic figure" (connecting 1-4-2-8-5-7).
The Enneagram of Personality has been widely promoted in both business management and spirituality contexts through seminars, conferences, books, magazines, and DVDs.
The heavy metal band Slipknot uses the star figure enneagram as a symbol.