The Collaborative International Dictionary of English v.0.48:

Crude \Crude\ (kr[udd]d), a. [Compar. Cruder (-[~e]r); superl.
   Crudest.] [L. crudus raw; akin to cruor blood (which flows
   from a wound). See Raw, and cf. Cruel.]
   1. In its natural state; not cooked or prepared by fire or
      heat; undressed; not altered, refined, or prepared for use
      by any artificial process; raw; as, crude flesh. "Common
      crude salt." --Boyle.
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            Molding to its will each successive deposit of the
            crude materials.                      --I. Taylor.
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   2. Unripe; not mature or perfect; immature.
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            I come to pluck your berries harsh and crude.
                                                  --Milton.
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   3. Not reduced to order or form; unfinished; not arranged or
      prepared; ill-considered; immature. "Crude projects."
      --Macaulay.
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            Crude, undigested masses of suggestion, furnishing
            rather raw materials for composition. --De Quincey.
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            The originals of Nature in their crude
            Conception.                           --Milton.
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   4. Undigested; unconcocted; not brought into a form to give
      nourishment. "Crude and inconcoct." --Bacon.
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   5. Having, or displaying, superficial and undigested
      knowledge; without culture or profundity; as, a crude
      reasoner.
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   6. (Paint.) Harsh and offensive, as a color; tawdry or in bad
      taste, as a combination of colors, or any design or work
      of art.
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WordNet (r) 3.0 (2006):

crude
    adj 1: not carefully or expertly made; "managed to make a crude
           splint"; "a crude cabin of logs with bark still on them";
           "rough carpentry" [syn: crude, rough]
    2: conspicuously and tastelessly indecent; "coarse language"; "a
       crude joke"; "crude behavior"; "an earthy sense of humor"; "a
       revoltingly gross expletive"; "a vulgar gesture"; "full of
       language so vulgar it should have been edited" [syn: crude,
       earthy, gross, vulgar]
    3: not refined or processed; "unrefined ore"; "crude oil" [syn:
       unrefined, unprocessed, crude] [ant: processed,
       refined]
    4: belonging to an early stage of technical development;
       characterized by simplicity and (often) crudeness; "the crude
       weapons and rude agricultural implements of early man";
       "primitive movies of the 1890s"; "primitive living conditions
       in the Appalachian mountains" [syn: crude, primitive,
       rude]
    5: devoid of any qualifications or disguise or adornment; "the
       blunt truth"; "the crude facts"; "facing the stark reality of
       the deadline" [syn: blunt, crude(a), stark(a)]
    6: not processed or subjected to analysis; "raw data"; "the raw
       cost of production"; "only the crude vital statistics" [syn:
       crude, raw]
    n 1: a dark oil consisting mainly of hydrocarbons [syn:
         petroleum, crude oil, crude, rock oil, fossil
         oil, oil]

Moby Thesaurus II by Grady Ward, 1.0:

225 Moby Thesaurus words for "crude":
   Doric, abhorrent, abominable, amateurish, arrested, avgas,
   backward, barbaric, barbarous, barnyard, base, beastly,
   below contempt, beneath contempt, blatant, blinding, blue, blunt,
   boorish, brazen, brazenfaced, brusque, cacophonous, caddish,
   cloddish, clodhopping, clumsy, coarse, colorful, contemptible,
   crass, crude oil, despicable, detestable, dirty, disgusting,
   doggerel, dysphemistic, earthy, embryonic, ethyl, ethyl gas,
   execrable, extravagant, fetid, filthy, flagrant, flaring, flashy,
   flaunting, forbidding, fossil oil, foul, fulsome, garish, gas,
   gasoline, gaudy, glaring, gorgeous, graceless, gross, harsh,
   hateful, heinous, high-octane gas, high-test, ignoble, ignorant,
   ill-bred, immature, improper, impure, in bad taste, in embryo,
   in ovo, in the rough, inadequate, inconcinnate, inconcinnous,
   inconsiderate, incorrect, indecent, indecorous, indelicate,
   ineffective, inelegant, inexpert, infelicitous, inferior,
   insensible, insensitive, kerosene, lead-free gas, loathsome, loud,
   loutish, louty, low, low-lead gas, lowbred, lurid, malodorous,
   mephitic, meretricious, miasmal, miasmic, motor oil, nasty, native,
   natural, nauseating, noisome, noxious, objectionable, obnoxious,
   obscene, obtrusive, odious, offensive, ore, original, outlandish,
   overbright, oversimple, paraffin, petrol, petroleum, poor,
   premium gas, prentice, primitive, rare, raunchy, raw, raw material,
   rebarbative, red, reductionistic, reductive, regular, repellent,
   repugnant, repulsive, revolting, ribald, rich ore, rich vein,
   risque, rock oil, rough, rough diamond, roughcast, roughhewn, rude,
   rudimental, rudimentary, run-of-mine, rustic, savage, screaming,
   sensational, shameless, shrieking, sickening, simplistic, smutty,
   spectacular, stinking, stunted, tactless, tasteless, tawdry,
   unanalyzed mass, unbaked, unblown, unboiled, uncivil, uncooked,
   uncourtly, uncouth, uncultivated, uncultured, uncut, undercooked,
   underdeveloped, underdone, undeveloped, undignified, undressed,
   unenlightened, uneuphonious, unfashioned, unfelicitous, unfeminine,
   unfinished, unformed, ungenteel, ungentle, ungentlemanly,
   ungraceful, ungraded, unhewn, unlabored, unladylike, unlicked,
   unlicked cub, unmatured, unpolished, unprocessed, unproficient,
   unrefined, unseemly, unskilled, unsolicitous, unsophisticated,
   unsorted, untaught, untrained, untreated, unworked, unwrought,
   vile, virgin soil, vulgar