How did the FLorida Keys get their name?

The name is derived from the Spanish word "cayo" meaning small island.
Cayo Hueso (Spanish pronunciation: [ˈkaʝo ˈweso]) is the original Spanish name for the island of Key West. Spanish-speaking people today also use the term Cayo Hueso when referring to Key West. It literally means "the Island of Bones". It is said that the island was littered with the remains (bones) from a Native American battlefield or burial ground. The most widely accepted theory of how the name changed to Key West is that it is a false-friend anglicization of the word, on the ground that the word hueso [ˈweso]) sounds like "west" in English.[2] Other theories of how the island was named are that the name indicated that it was the westernmost Key,[3] or that the island was the westernmost Key with a reliable supply of water