n. 九个一组

[ noun ]
the cardinal number that is the sum of eight and one
<noun.quantity>

Ennead \En"ne*ad\, n. [Gr. ?, ?, fr. 'enne`a nine.]
The number nine or a group of nine.

{The Enneads}, the title given to the works of the
philosopher Plotinus, published by his pupil Porphyry; --
so called because each of the six books into which it is
divided contains nine chapters.