This is the 5782nd most frequent Polish word.
zabitych
"Zabitych" means "of the killed" or "killed" in English, typically used in the genitive plural form.
Here, 'zabitych' is used as an adjective derived from the past participle of 'zabić' (to kill), being in the genitive plural form to describe 'liczbę' (the number of people who perished).
Policja ogłosiła liczbę zabitych w wypadku samochodowym.
The police have announced the number of fatalities in the car accident.
In this example, 'zabitych' refers to animals that have been killed, used as an adjective describing 'zwierząt' (animals) in genitive plural.
Znaleziono schronienie dla zabitych zwierząt.
Shelter was found for the killed animals.
Here, 'zabitych' is describing 'osób' (people) in genitive plural, referring to those killed during a war scenario.