This is the 14853rd most frequent Russian word.
поврежденная
Damaged.
The word 'поврежденный' is the masculine singular form of 'поврежденная', modifying 'почтовый ящик' (mailbox), which is in the masculine singular form to agree with its gender and case.
Он доставил письмо в поврежденный почтовый ящик.
He delivered the letter to the damaged mailbox.
The word 'поврежденная' is used here as an adjective describing the noun 'машина' (car), indicating its damaged state.
Поврежденная машина стояла на обочине.
The damaged car was standing by the roadside.
In this sentence, 'поврежденную' is the accusative feminine singular form of 'поврежденная', describing the noun 'дверь' (door), which is in the accusative case because it's the direct object of the verb 'обошла' (walked around).