1.
nine
The number nine. Like four, nine has two readings: きゅう and く. きゅう is more common because く sounds like 苦 (suffering), making it somewhat inauspicious.
I work from nine in the morning to six in the evening every day.
九時 uses the く reading
九 has two on'yomi readings: きゅう and く. Both are valid, but く can sound like 苦 (suffering), so きゅう is often preferred.
Readings by context
- 九時: nine o'clock (く is standard here)
- 九月: September (く reading)
- 九百: nine hundred (きゅう)
- 九つ: nine (native Japanese counter)
Superstition
Like 四 (which sounds like 死, death), 九 is considered somewhat unlucky because it sounds like 苦 (suffering). Hospital rooms and hotel floors sometimes skip the number 9.