The Collaborative International Dictionary of English v.0.48:

Rude \Rude\, a. [Compar. Ruder; superl. Rudest.] [F., fr. L.
   rudis.]
   1. Characterized by roughness; umpolished; raw; lacking
      delicacy or refinement; coarse.
      [1913 Webster]

            Such gardening tools as art, yet rude, . . . had
            formed.                               --Milton.
      [1913 Webster]

   2. Hence, specifically:
      (a) Unformed by taste or skill; not nicely finished; not
          smoothed or polished; -- said especially of material
          things; as, rude workmanship. "Rude was the cloth."
          --Chaucer.
          [1913 Webster]

                Rude and unpolished stones.       --Bp.
                                                  Stillingfleet.
          [1913 Webster]

                The heaven-born child
                All meanly wrapt in the rude manger lies.
                                                  --Milton.
          [1913 Webster]
      (b) Of untaught manners; unpolished; of low rank; uncivil;
          clownish; ignorant; raw; unskillful; -- said of
          persons, or of conduct, skill, and the like. "Mine
          ancestors were rude." --Chaucer.
          [1913 Webster]

                He was but rude in the profession of arms. --Sir
                                                  H. Wotton.
          [1913 Webster]

                the rude forefathers of the hamlet sleep.
                                                  --Gray.
          [1913 Webster]
      (c) Violent; tumultuous; boisterous; inclement; harsh;
          severe; -- said of the weather, of storms, and the
          like; as, the rude winter.
          [1913 Webster]

                [Clouds] pushed with winds, rude in their shock.
                                                  --Milton.
          [1913 Webster]

                The rude agitation [of water] breaks it into
                foam.                             --Boyle.
          [1913 Webster]
      (d) Barbarous; fierce; bloody; impetuous; -- said of war,
          conflict, and the like; as, the rude shock of armies.
      (e) Not finished or complete; inelegant; lacking
          chasteness or elegance; not in good taste;
          unsatisfactory in mode of treatment; -- said of
          literature, language, style, and the like. "The rude
          Irish books." --Spenser.
          [1913 Webster]

                Rude am I in my speech.           --Shak.
          [1913 Webster]

                Unblemished by my rude translation. --Dryden.
          [1913 Webster]

   Syn: Impertinent; rough; uneven; shapeless; unfashioned;
        rugged; artless; unpolished; uncouth; inelegant; rustic;
        coarse; vulgar; clownish; raw; unskillful; untaught;
        illiterate; ignorant; uncivil; impolite; saucy;
        impudent; insolent; surly; currish; churlish; brutal;
        uncivilized; barbarous; savage; violent; fierce;
        tumultuous; turbulent; impetuous; boisterous; harsh;
        inclement; severe. See Impertiment.
        [1913 Webster] -- Rude"ly, adv. -- Rude"ness, n.
        [1913 Webster]

WordNet (r) 3.0 (2006):

rude
    adj 1: socially incorrect in behavior; "resentment flared at
           such an unmannered intrusion" [syn: ill-mannered, bad-
           mannered, rude, unmannered, unmannerly]
    2: (of persons) lacking in refinement or grace [syn: ill-bred,
       bounderish, lowbred, rude, underbred, yokelish]
    3: lacking civility or good manners; "want nothing from you but
       to get away from your uncivil tongue"- Willa Cather [syn:
       uncivil, rude] [ant: civil, polite]
    4: (used especially of commodities) being unprocessed or
       manufactured using only simple or minimal processes; "natural
       yogurt"; "natural produce"; "raw wool"; "raw sugar"; "bales
       of rude cotton" [syn: natural, raw(a), rude(a)]
    5: 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]

The Free On-line Dictionary of Computing (19 January 2023):

rude

   [WPI] 1. Badly written or functionally poor, e.g. a program
   that is very difficult to use because of gratuitously poor
   design decisions.  Opposite: cuspy.

   2. Anything that manipulates a shared resource without regard
   for its other users in such a way as to cause a (non-fatal)
   problem.  Examples: programs that change tty modes without
   resetting them on exit, or windowing programs that keep
   forcing themselves to the top of the window stack.  Compare
   all-elbows.

   [Jargon File]

   (1994-10-27)


The Jargon File (version 4.4.7, 29 Dec 2003):

rude
 adj.

    1. (of a program) Badly written.

    2. Functionally poor, e.g., a program that is very difficult to use because
    of gratuitously poor (random?) design decisions. Oppose cuspy.

    3. Anything that manipulates a shared resource without regard for its other
    users in such a way as to cause a (non-fatal) problem. Examples: programs
    that change tty modes without resetting them on exit, or windowing programs
    that keep forcing themselves to the top of the window stack.