This is the 14720th most frequent Russian word.
петрушку
Parsley.
Here, 'петрушку' is used in the accusative case as the direct object of the verb 'купил' to refer to the herb parsley.
Я купил свежую петрушку на рынке.
I bought fresh parsley at the market.
In this case, 'петрушку' is again used in the accusative case as the direct object of the verb 'добавила' to describe the ingredient being added.
Она добавила петрушку в суп, чтобы улучшить вкус.
She added parsley to the soup to enhance the flavor.
Here, 'петрушки' is used in the genitive case to indicate absence or lack of parsley in the dish.