This is the 923rd most frequent Ukrainian word.
зима
Winter.
Here, 'зима' is used as the noun 'winter', denoting the season in a general descriptive context.
Зима прийшла, і ми купили теплий одяг.
Winter has come, and we bought warm clothes.
In this sentence, 'зими' (plural of 'зима') is used to refer to winters in general, highlighting their characteristics.
У цьому місті зими дуже холодні.
In this city, winters are very cold.
'Зимою' is used as an adverbial expression of time, specifying the period when the action occurs.