The Collaborative International Dictionary of English v.0.48:

Mab \Mab\ (m[a^]b), prop. n. [Cf. W. mad a male child, a boy.]
   [1913 Webster]
   1. A slattern. [Prov. Eng.]
      [1913 Webster]

   2. [capitalized] The name of a female fairy, esp. the queen
      of the fairies; and hence, sometimes, any fairy. --Shak.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

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