This is the 12698th most frequent Polish word.
nienawidzi
"Hates."
The word 'nienawidzi' is used here as a verb in the third person singular present tense to describe a strong dislike towards 'zimy' (winter).
Ona nienawidzi zimy.
She hates winter.
In this sentence, 'nienawidzi' is used to express an aversion towards an activity (running), with 'biegać' being the infinitive form of the verb.
Dlaczego on nienawidzi biegać?
Why does he hate running?
Here, while the word is altered (nienawidzą) to agree with the plural subject 'Dzieci' (Children), it maintains its role as a verb showing dislike.