This is the 13786th most frequent Russian word.
новогодним
"Новогодним" means "relating to the New Year" or "New Year's."
The word 'новогодними' here is used as an adjective in the instrumental plural form, modifying 'украшениями,' indicating the type of decorations related to the New Year.
Мы украсили дом новогодними украшениями.
We decorated the house with New Year's decorations.
In this sentence, 'новогодними' appears as an adjective in the instrumental plural form, describing 'планами' (plans) to specify that these are plans related to the New Year celebrations.
Она поделилась своими новогодними планами.
She shared her New Year's plans.
Here, 'новогодними' serves as an adjective in the instrumental plural form, illustrating the type of 'ароматами' (aromas) related to the context of New Year.