How did a jellyfish get its name?

Jellyfish tend to look like piles of really gross jelly when they're out of the water.

Thus, jellyfish.Jelly fishes are one of the primitive animals that have lived in the oceans for more than 550 million years .They belong to a group of animals called the Coelenterata. Actually,how jelly fish get their names is not exactly known, that's few that i came across about jelly fishes.