enne

Enne is not a common stand-alone term in English. It is most often encountered as a fragment of the Greek-derived combining form ennea-, meaning nine. In English, the combining form is typically rendered as ennea- or enne-, and it appears in several related terms that refer to groups of nine or ninefold structures.

Prominent uses include Ennead, a group of nine, most famously the Great Ennead of Egyptian mythology, a classical constellation of nine deities centered in Heliopolis. Enneagram refers to a nine-pointed figure used in various spiritual, psychological, and mathematical contexts; the prefix ennea- combines with gramma, meaning writing or diagram, to describe the nine-point diagram. Enneagon is a nine-sided polygon; while correct, it is far less common in modern usage than nonagon, the term that has become more widespread in everyday mathematics. Enneahedron (or enneAhedron) denotes a nine-faced polyhedron, though such terms are rare outside geometric discourse.

In broader scholarly and cultural contexts, enne- appears primarily as a prefix indicating nine, rather than as an independent word. The term Ennead also extends to literary and philosophical discussions about groups of nine, beyond mythology. Because English usage favors nonagon over enneagon and non-technical references over ennea- forms, instances of enne- tend to occur mainly in technical vocabulary, historical texts, or discussions of Greek numerals.

See also: ennea-, Greek numerals, ennead, enneagram, enneagon, ennehedron.