Gnome
A gnome is a diminutive spirit in Renaissance magic and alchemy, first introduced by Paracelsus in the 16th century and later adopted by more recent authors including those of modern fantasy literature. Its characteristics have been reinterpreted to suit the needs of various story tellers, but it is typically said to be a small, humanoid creature that lives underground.
History
Origins
The word comes from Renaissance Latin gnomus, which first appears in the works of 16th century Swiss alchemist Paracelsus, possibly deriving the term from Latin gēnomos (itself representing a Greek γη-νομος, literally "earth-dweller"). In this case, the omission of the ē is, as the Oxford English Dictionary (OED) calls it, a blunder. Alternatively, the term may be an original invention of Paracelsus.
Paracelsus uses Gnomi as a synonym of Pygmæi, and classifies them as earth elementals. He describes them as two spans high, very reluctant to interact with humans, and able to move through solid earth as easily as humans move through air.