This is the 9557th most frequent Spanish word.
apearon
"Apearon" means "they dismounted" or "they got off" (from a horse, vehicle, etc.).
Usage here indicates the action of alighting or descending from a mode of transportation.
Los viajeros se apearon del tren en la estación central de la ciudad.
The travelers disembarked the train at the city's central station.
In this sentence, it describes the action of getting off a horse after riding it.
Con cuidado, se apearon del caballo tras la larga jornada.
Carefully, they alighted from the horse after the long journey.
Here, the word is used in a colloquial sense to imply unloading items from a vehicle.