nonuple

This term is highly specialized and rare in everyday conversation, typically appearing in mathematical, musical, or technical contexts. It carries a formal, precise tone and is often replaced by the phrase "nine times" or "ninefold" in general speech to avoid sounding overly archaic or academic.

When used as a noun to describe a group of nine, it follows the pattern of terms like trio or quartet, though it is significantly less common. In these instances, it refers to the collective entity rather than the individual members.