This is the 17537th most frequent Russian word.
тревожной
"Anxious" or "alarming."
Describes the state of the night being full of anxiety.
Тревожной ночью она не могла уснуть.
On an anxious night, she couldn't fall asleep.
Indicates a quality of the contemplation being tinged with anxiety.
Её взгляд был полон тревожной задумчивости.
Her gaze was filled with anxious contemplation.
Attributes the music with a characteristic of evoking anxiety.