This is the 4735th most frequent Russian word.
задержанного
"Задержанного" means "detained person" or "someone who has been detained."
In this sentence, 'задержанного' is used as an adjective-derived noun referring to the individual who has been detained, describing their current condition of being detained.
Полицейские проверяли документы задержанного.
The police were checking the detainee's documents.
Here, 'задержанного' serves as an adjective functioning nominally, specifying the individual who was detained, focusing on their legal status.
Адвокат требовал освобождения задержанного.
The attorney demanded the release of the detained person.
In this case, 'задержанного' denotes the person being detained, encapsulating the concept of both their state and action contextually related to their situation.