Yes, night is a Scrabble word!

Noun

1. The time after sunset and before sunrise while it is dark outside

2. A period of ignorance or backwardness or gloom

3. The period spent sleeping

4. The dark part of the diurnal cycle considered a time unit

5. Darkness

6. A shortening of nightfall

7. The time between sunset and midnight

8. Roman goddess of night; daughter of Erebus; counterpart of Greek Nyx