This is the 15573rd most frequent Polish word.
straszliwych
"Straszliwych" means "terrible" or "horrible" (plural form, genitive or accusative case).
The word 'straszliwych' is used here as an adjective in the genitive plural to describe the nature of the 'monsters', emphasizing their dreadful characteristic.
W lesie widziałem ślady straszliwych potworów.
In the forest, I saw traces of dreadful monsters.
In this sentence, 'straszliwych' functions as an adjective in the genitive plural, modifying 'burzach' to highlight the threatening and intense nature of the storms.
Ludzie opowiadali historie o straszliwych nocnych burzach.
People told stories about dreadful night storms.
Here, 'straszliwych' serves as an adjective in the genitive plural, describing 'skutków' to underline the severe and alarming impact of the consequences.