The Collaborative International Dictionary of English v.0.48:

Hermit \Her"mit\, n. [OE. ermite, eremite, heremit, heremite, F.
   hermite, ermite, L. eremita, Gr. ?, fr. ? lonely, solitary.
   Cf. Eremite.]
   1. A person who retires from society and lives in solitude; a
      recluse; an anchoret; especially, one who so lives from
      religious motives.
      [1913 Webster]

            He had been Duke of Savoy, and after a very glorious
            reign, took on him the habit of a hermit, and
            retired into this solitary spot.      --Addison.
      [1913 Webster]

   2. A beadsman; one bound to pray for another. [Obs.] "We rest
      your hermits." --Shak.
      [1913 Webster]

   3. (Cookery) A spiced molasses cookie, often containing
      chopped raisins and nuts.
      [Webster 1913 Suppl.]

   Hermit crab (Zool.), a marine decapod crustacean of the
      family Pagurid[ae]. The species are numerous, and belong
      to many genera. Called also soldier crab. The hermit
      crabs usually occupy the dead shells of various univalve
      mollusks. See Illust. of Commensal.

   Hermit thrush (Zool.), an American thrush (Turdus
      Pallasii), with retiring habits, but having a sweet song.


   Hermit warbler (Zool.), a California wood warbler
      (Dendroica occidentalis), having the head yellow, the
      throat black, and the back gray, with black streaks.
      [1913 Webster]

WordNet (r) 3.0 (2006):

hermit
    n 1: one retired from society for religious reasons [syn:
         anchorite, hermit]
    2: one who lives in solitude [syn: hermit, recluse,
       solitary, solitudinarian, troglodyte]

Moby Thesaurus II by Grady Ward, 1.0:

97 Moby Thesaurus words for "hermit":
   Albigensian, Catharist, Diogenes, Franciscan, Hieronymian,
   Hieronymite, Sabbatarian, Timon of Athens, Trappist, Waldensian,
   abbacomes, abbot, abstainer, alien, anchoress, anchoret, anchorite,
   ascetic, beadsman, bedridden invalid, bhikshu, brother, caloyer,
   case, celibate, cenobite, character, cloistered monk, closet cynic,
   conventual, conventual prior, crackpot, crank, dervish,
   desert fathers, desert saints, eccentric, eremite, fakir, fanatic,
   flagellant, friar, grand prior, hermitess, hieromonach, hobo,
   homebody, invalid, isolationist, kook, lay abbot, lay brother,
   lone wolf, loner, marabout, maverick, mendicant, meshuggenah,
   monastic, monk, natural, nonconformist, nut, odd fellow, oddball,
   oddity, original, outcast, outsider, palmer, pariah, pilgrim,
   pillar saint, pillarist, prior, puritan, queer duck, queer fish,
   queer specimen, rara avis, recluse, religieux, religious, sannyasi,
   screwball, seclusionist, shut-in, solitaire, solitary,
   solitudinarian, stay-at-home, stylite, tramp, type, yogi, yogin,
   zealot



The Devil's Dictionary (1881-1906):

HERMIT, n.  A person whose vices and follies are not sociable.