This is the 11549th most frequent Russian word.
дрожащих
"Quivering" or "trembling."
In this sentence, 'дрожащих' functions as an adjective in the genitive plural case, modifying the noun 'windows.' It signifies the windows vibrating or shaking.
Её голос пробился через звук дрожащих окон.
Her voice broke through the sound of the trembling windows.
Here, 'дрожащих' is also an attributive adjective in the genitive plural case, describing 'people.' It conveys the idea of people shivering due to the cold.
На экране показали лица дрожащих людей в холоде.
The screen showed faces of trembling people in the cold.
The word 'дрожащих' is used as an adjective in the genitive plural case, describing the birds. It translates to 'trembling,' indicating an act or state of shivering or quivering.