This is the 12733rd most frequent Polish word.
nieprzytomnego
"Nieprzytomnego" means "unconscious."
In this sentence, 'nieprzytomnego' is an adjective used in its accusative form to describe the state of the man who was found as unconscious.
Ratownicy odnaleźli nieprzytomnego mężczyznę w lesie.
Rescuers found an unconscious man in the forest.
Here, 'nieprzytomnego' is the instrumental form of the adjective used to describe the patient, indicating their unconscious state.
Opiekunka musiała zaopiekować się nieprzytomnym pacjentem.
The caregiver had to take care of the unconscious patient.
In this example, 'nieprzytomnego' modifies the noun 'dog' to convey that the dog described is unconscious, an adjective in usage.