The Collaborative International Dictionary of English v.0.48:

Goblin \Gob"lin\, n. [OE. gobelin, F. gobelin, LL. gobelinus,
   fr. Gr. ? knave, a mischievous goblin; or cf. G. kobold, E.
   kobold, cobalt, Armor. gobilin an ignis fatuus, goblin.]
   An evil or mischievous spirit; a playful or malicious elf; a
   frightful phantom; a gnome.
   [1913 Webster]

         To whom the goblin, full of wrath, replied. --Milton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

goblin
    n 1: (folklore) a small grotesque supernatural creature that
         makes trouble for human beings [syn: goblin, hob,
         hobgoblin]

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "goblin":
   Ariel, Befind, Corrigan, Finnbeara, Mab, Oberon, Titania, banshee,
   brownie, cluricaune, demon, dwarf, elf, fairy, fairy queen, fay,
   gnome, gremlin, hob, hobgoblin, imp, kobold, leprechaun, nix,
   nixie, ouphe, peri, pixie, pooka, puca, pwca, sprite, sylph,
   sylphid