Source : Webster's Revised Unabridged Dictionary (1913)

Uncouth \Un*couth"\, a. [OE. uncouth, AS. unc?? unknown,
   strange: un- (see {Un-} not) + c?? known, p. p. of cunnan to
   know. See {Can} to be able, and cf. {Unco}, {Unked}.]
   1. Unknown. [Obs.] ``This uncouth errand.'' --Milton.

            To leave the good that I had in hand, In hope of
            better that was uncouth.              --Spenser.

   2. Uncommon; rare; exquisite; elegant. [Obs.]

            Harness . . . so uncouth and so rish. --Chaucer.

   3. Unfamiliar; strange; hence, mysterious; dreadful; also,
      odd; awkward; boorish; as, uncouth manners. ``Uncouth in
      guise and gesture.'' --I. Taylor.

            I am surprised with an uncouth fear.  --Shak.

            Thus sang the uncouth swain.          --Milton.

   Syn: See {Awkward}. -- {Un*couth"ly}, adv. --
        {Un*couth"ness}, n.

Source : WordNet®

uncouth
     adj : lacking refinement or cultivation or taste; "he had coarse
           manners but a first-rate mind"; "behavior that branded
           him as common"; "an untutored and uncouth human being";
           "an uncouth soldier--a real tough guy"; "appealing to
           the vulgar taste for violence"; "the vulgar display of
           the newly rich" [syn: {coarse}, {common}, {rough-cut},
           {vulgar}]