This is the 9116th most frequent Russian word.
саранчой
The Russian word "саранчой" is the instrumental singular form of "саранча," meaning "locust" (used in the sense of "with locust" or "by locust").
Here, 'саранчой' serves as an instrumental case of 'саранча', meaning 'locust', showing the means or tools used.
Саранчой покрыли поле, угрожая урожаю.
The locusts covered the field, threatening the harvest.
In this sentence, 'саранчой' is used figuratively to describe the abundance of locusts on the meadow.
Дети смотрели на саранчой поляну с ужасом.
The children watched the meadow covered with locusts in horror.
Here 'саранчой' is the object of action in the instrumental case, indicating with what the action was done or against whom it was directed.