This is the 11325th most frequent Polish word.
huśtawka
"Huśtawka" in English means "swing."
In this sentence, 'huśtawka' refers to a physical swing that is typically found in playgrounds.
Dzieci bawią się na huśtawce w parku.
The children are playing on the swing in the park.
Here, 'huśtawka' is used metaphorically to describe an emotional swing or fluctuation.
Czułam się, jakbym była na emocjonalnej huśtawce.
I felt as if I were on an emotional seesaw.
In this instance, 'huśtawka' is part of the expression 'huśtawka nastrojów,' meaning mood swing.