The Collaborative International Dictionary of English v.0.48:

hick \hick\ n.
   A person who is not very intelligent or interested in
   culture; a hayseed.

   Syn: yokel, rube, yahoo, hayseed, bumpkin, chawbacon.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

hick \hick\ adj.
   1. rural. Opposite of urban.
      [WordNet 1.5]

   2. characteristic of rural people, especially those not
      knowledgeable about matters outside their locality; as,
      hick ideas; a hick town.

   Syn: bumpkinly, rustic, unsophisticated.
        [WordNet 1.5] hickey

WordNet (r) 3.0 (2006):

hick
    adj 1: awkwardly simple and provincial; "bumpkinly country
           boys"; "rustic farmers"; "a hick town"; "the nightlife of
           Montmartre awed the unsophisticated tourists" [syn:
           bumpkinly, hick, rustic, unsophisticated]
    n 1: a person who is not very intelligent or interested in
         culture [syn: yokel, rube, hick, yahoo, hayseed,
         bumpkin, chawbacon]

Moby Thesaurus II by Grady Ward, 1.0:

74 Moby Thesaurus words for "hick":
   babe, boor, boorish, bucolic, bumpkin, butterfingers, child,
   child of nature, churlish, clod, cloddish, clodhopper, clodhopping,
   clown, clownish, clumsy, countrified, country bumpkin,
   country-born, country-bred, dove, dub, duffer, dupe, farmer,
   farmerish, foozler, foul-up, from the sticks, fumble-fist, gawk,
   gawky, goof, goofball, goofer, hayseed, hicky, hillbilly,
   hobnailed, infant, ingenue, innocent, inurbane, lamb, looby, lout,
   loutish, lubber, lummox, lump, lumpen, lumpish, mere child, muff,
   muffer, noble savage, oaf, provincial, rube, rustic, simple soul,
   slob, stumblebum, stumblebunny, uncouth, uncultivated, uncultured,
   unpolished, unrefined, unsophisticate, up-country, whistle-stop,
   yokel, yokelish