The modern word "nine" derives directly from the Old English world nigen. and indirectly from the hypothetical PIE root (e)newn.
A multiple birth of nine is called nonuplets
a nonagon is the name given to a nine sided polygon
Nonagon
Nonagon
Nonagon
D9
Nine Steps of Sales Call
CALL OF DUTY 9 VENDETTA or CALL OF DUTY 9 BLOOD BROTHERS
A Nonagon
it is called a nonagon.
nine-lined poem
Nine months.