Not sure I agree with your etymology, giuseppe.
Besides, the safety of the reading Gerasene is shaky, although the scene could have occurred in the geographical vicinity of that town due to the steep slope to the Lake of Galilee.
Since all the towns of the Decapolis region were established by Alexander the Great and the Greek successors to him as Greek style city-states (the polis), where they settled the veterans of their armies, I do not believe that any of them were placed at previously established Syrian towns. So, we can largely rule out an Aramaic or Hebrew etymology. My guess for the name Gerasa for this Greek colony would be the Greek word GE (= ground) plus RHIZA (root). Or simply GERAS (old age). Basically: "Place of Retirement" or "A good place to plant roots." Naturally, if they are to farm the land granted to the polis, they have to plant grain in the earth. The possibilities are, it seems, endless.
My own suggestion, made many moons ago on Crosstalk2, was the account is roughly based on the following passage:
Wars of the Jews 2:503-506 wrote: wrote:
503 so Cestius took part of his forces and marched hastily to Zebulun, a strong city of Galilee, which was called the City of Men, and divides the country of Ptolemais from our nation; 504 this he found deserted by its men, the multitude having fled to the mountains, but full of all sorts of good things; those he allowed the soldiers to plunder, and set fire to the city, although it was of admirable beauty, and had its houses built like those in Tyre, and Sidon, and Berytus. 505 After this he overran all the country, and seized upon whatever came in his way, and set fire to the villages that were around them, and then returned to Ptolemais. 506 But when the Syrians, and especially those of Berytus, were busy in plundering, the Jews pulled up their courage again, for they knew that Cestius had retired, and attacked those who were left behind unexpectedly, and killed about two thousand of them.
This Zebulun would presumably have existed in the mountain region between Ptolemais (on the Mediterranean Sea) and the Sea of Galilee (and thus be on exactly the opposite side of the Sea of Galilee than Gadara or Gerasa, probably in fact not far from Jotapata or Asochis).
I suggested that this rout was perceived in a manner similar to the way the Arab PLO nationalists used to speak of "pushing the Jews back into the sea" in the 1970s, except here it was Roman forces being pushed back to the shores of the Mediterranean Sea. Granted the soldiers were Roman auxiliaries, not legionnaires, but when boasting, folks do tend to exaggerate.
IMHO, have here (in Gospel of Mark) a remnant of Judean propaganda from the first rebellion of 66-74 CE. If Jesus' death was a real one, and actually occurred in the times of Pilate, I do think that it is possible that the later events of the Judean War had somehow affected the telling of his story.