This is the 5472nd most frequent Russian word.
погибшим
"Погибшим" means "to the deceased" or "to those who died."
In this sentence, "погибшим" is used as an adjective in the dative case to describe those who perished, typically in war or a tragic event.
Мы возложили цветы к памятнику погибшим.
We laid flowers at the monument to the fallen.
Here, "погибшим" is an adjective in the dative case used as a substantive, referring collectively to individuals who lost their lives in disasters.
Этот фильм посвящён погибшим в катастрофах.
This film is dedicated to those who perished in disasters.
In this usage, "погибшим" is in the dative case because it serves as the indirect object of the verb, referring to the deceased individuals.