This is the 17660th most frequent Polish word.
zjadły
"Zjadły" means "they ate" in English.
Here, 'zjadły' is the past tense form of 'to eat' used for feminine plural subjects, denoting completed eating action by the subject 'cats'.
Koty zjadły całe jedzenie.
The cats ate all the food.
Here, 'zjadły' reflects the past action performed by feminine plural subjects (girls), indicating they completed eating the cake.
Dziewczyny zjadły ciasto na przyjęciu.
The girls ate the cake at the party.
In this context, 'zjadły' signifies the completed past action by feminine plural subjects ('sisters') regarding eating their dinner.