This is the 15232nd most frequent Russian word.
пораженные
"Afflicted" or "affected."
Here, 'пораженные' is used as an adjective to describe the trees ('деревья') that have been affected by some external factor, such as a disease, signifying its descriptive use.
Пораженные деревья стали засыхать.
The affected trees began to wither.
In this sentence, 'пораженные' is employed as a participle expressing the state of being impressed or struck ('пораженные') by something remarkable ('их смелостью').
Пораженные их смелостью, мы не знали, как реагировать.
Struck by their courage, we didn't know how to react.
Here, 'пораженные' serves as an adjective modifying 'участки кожи' ('areas of skin'), indicating those portions that are affected by some condition, such as irritation or infection.