night-night
interjectionUK /ˌnaɪtˈnaɪt/
US /ˌnaɪtˈnaɪt/
A cute way to say good night when you go to bed.
Mom kissed me and said, "Night-night, sleep tight!"
OTHER MEANINGS
2. A childish or playful name for bedtime or going to sleep.
It's night-night time, so put your toys away.
3. A gentle farewell said to someone going to sleep, often to a child.
He waved night-night to his baby sister.
4. Used to describe a sleepy or tired feeling, especially in children's talk.
After the long trip, the kids were all night-night in the car.