night owl
/ˈnaɪt aʊl/noun
High School
1
An owl (order Strigiformes) that is nocturnal.
2
One who goes to bed late, or stays up late at night or in the early hours of the morning.
3
A musical instrument which imitates an owl's hoot, consisting of a receptacle partly filled with water and a mouthpiece that is blown into.