elf

noun6

1. •
   A supernatural being or spirit associated with illness, mischief, and harmful or dangerous magical influence; in later Norse sources, sometimes divided into benevolent light elves (inhabiting Álfheimr) and malevolent dark elves.

   • Every elf, and fairy sprite, Hop as light as bird from brier. — 1595
2. •
   A small, magical creature similar to a fairy, often mischievous, playful, or occasionally helpful.

   • For there and several other places About mill dams and green brae faces, Both Elrich, Elfs and Brownies stayed, And Green gown’d Farries daunc’d and played; […] — 1690
3. •
   A member of a race of tall, slender, graceful beings with pointed ears, typically immortal or very long-lived and possessing wisdom and magical abilities.

   • Much of fairy lore clusters around the so-called fairy rings, that is, the green circles in old pastures within which the elfs were supposed to dance at night by the light of the moon. — 1889
4. •
   Ellipsis of Christmas elf.

   • Since you’ve been out, the news arrives The Elfs’ Insurance Company’s gone. — 1877
5. •
   (South-Africa) Bluefish (Pomatomus saltatrix).
6. •
   (no longer used) A very diminutive person; a dwarf.

verb1

1. •
   (no longer used) To twist into elflocks (of hair); to mat.

   • My face I'll grime with filth, blanket my loins, elf all my hairs in knots, and with presented nakedness outface the winds and persecutions of the sky. — 1603

noun3

1. •
   Initialism of extremely low frequency.
2. •
   Acronym of English as a lingua franca (“English used by non-native speakers”).
3. •
   Acronym of Executable and Linking Format, a common object file format for Unix.