This is the 5204th most frequent Russian word.
новогоднее
"Новогоднее" means "New Year's" or "related to New Year."
In this context, 'новогоднее' is an adjective describing 'украшение', specifying that the decoration is related to the New Year's theme.
Я купил новогоднее украшение для елки.
I bought a New Year's decoration for the Christmas tree.
Here, 'новогоднее' is an adjective modifying 'настроение', indicating that the mood is specific to the New Year's celebration.
Новогоднее настроение ощущается повсюду.
The New Year's mood is felt everywhere.
In this sentence, 'новогоднее' is an adjective qualifying 'кино', signifying that the movie is themed around New Year's.