1The number nine (9); indicating nine units or the ninth in a series. The main readings are the Sino-Japanese きゅう, the older Sino-Japanese く, and the native-Japanese ここの. The reading く survives in fixed words like 九月 (くがつ, September) and 九時 (くじ, nine o'clock), but because く is a homophone of 苦 ('suffering'), it is sometimes avoided for room numbers in hospitals and the like. ここの is used in everyday compounds like 九つ (ここのつ, 'nine things') and 九日 (ここのか, 'ninth day'). The variant 玖 is used in legal documents to prevent forgery.
会議は午前九時に始まります。
The meeting starts at nine in the morning.
九月九日は古来より重陽の節句として祝われてきた。
September 9th has been celebrated since ancient times as the Chrysanthemum Festival.
テーブルの上に皿が九つ並んでいる。
There are nine plates lined up on the table.
病院では「九」が「苦」と同じ音であることから、九号室を避けることもある。
Hospitals sometimes skip Room 9 because く ('nine') sounds the same as 苦 ('suffering').
今年九十歳になる祖父は今もとても元気だ。
My grandfather, who turns ninety this year, is still very active.
領収書には「金玖万円」と書かれていた。
The receipt was written 金玖万円 (ninety thousand yen) using the legal form of 'nine'.