What does "elf" mean?

Elf: A very diminutive person; a dwarf. Elf arrow, a flint arrowhead; - - so called by the English rural folk who often find these objects of prehistoric make in the fields and formerly attributed them to fairies; -- called also elf bolt, elf dart, and elf shot. -- Elf child, a child supposed to be left by elves, in room of one they had stolen. See Changeling. -- Elf fire, the ignis fatuus. Brewer. -- Elf owl (Zoöl.), a small owl (Micrathene Whitneyi) of Southern California and Arizona.