The Collaborative International Dictionary of English v.0.48:

Inept \In*ept"\, a. [L. ineptus; prefix. in- not + aptus apt,
   fit: cf. F. inepte. Cf. Inapt.]
   [1913 Webster]
   1. Not apt or fit; unfit; unsuitable; improper; unbecoming.
      [1913 Webster]

            The Aristotelian philosophy is inept for new
            discoveries.                          --Glanvill.
      [1913 Webster]

   2. Silly; useless; nonsensical; absurd; foolish.
      [1913 Webster]

            To view attention as a special act of intelligence,
            and to distinguish it from consciousness, is utterly
            inept.                                --Sir W.
                                                  Hamilton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

inept
    adj 1: not elegant or graceful in expression; "an awkward prose
           style"; "a clumsy apology"; "his cumbersome writing
           style"; "if the rumor is true, can anything be more inept
           than to repeat it now?" [syn: awkward, clumsy,
           cumbersome, inapt, inept, ill-chosen]
    2: generally incompetent and ineffectual; "feckless attempts to
       repair the plumbing"; "inept handling of the account" [syn:
       feckless, inept]
    3: revealing lack of perceptiveness or judgment or finesse; "an
       inept remark"; "it was tactless to bring up those
       disagreeable" [syn: inept, tactless]

Moby Thesaurus II by Grady Ward, 1.0:

178 Moby Thesaurus words for "inept":
   apish, artless, asinine, awkward, bad, batty, befooled, beguiled,
   besotted, brainless, buffoonish, bumbling, bungling, clumsy,
   cockeyed, crazy, credulous, daffy, daft, dazed, dizzy, doting,
   dumb, fatuitous, fatuous, flaky, fond, fool, foolheaded, foolish,
   fuddled, futile, gaga, gauche, goofy, graceless, gulled,
   half-assed, halting, ham-handed, headless, idiotic, ignorant,
   ill-adapted, ill-advised, ill-assorted, ill-chosen, ill-considered,
   ill-fitted, ill-judged, ill-matched, ill-sorted, ill-suited,
   ill-timed, imbecile, impolitic, improper, imprudent, inadept,
   inadmissible, inadvisable, inane, inapplicable, inapposite,
   inappropriate, inapt, inattentive, incapable, incapable of,
   incompetent, incongruous, indiscreet, ineffective, inefficient,
   inexpedient, inexpert, infatuated, infelicitous, inferior,
   injudicious, inopportune, insane, insensate, irrational,
   irrelevant, kooky, lackbrained, lean-minded, lean-witted, loony,
   lumbering, mad, mal a propos, maladjusted, maladroit, malapropos,
   maudlin, mediocre, mindless, misguided, misjoined, mismatched,
   mismated, misplaced, moronic, not bright, nutty, of little brain,
   out of character, out of joint, out of keeping, out of line,
   out of place, out of proportion, out of season, out of time,
   out of tune, pea-brained, pedestrian, pin-brained, poor,
   reasonless, sappy, screwy, senseless, sentimental, silly,
   skill-less, slackminded, slackwitted, stupid, thoughtless, unable,
   unable to, unadapted, unadvised, unapt, unbecoming, unbefitting,
   undeft, undesirable, undexterous, undextrous, undiplomatic, undue,
   unendowed, unfacile, unfit, unfitted, unfitting, unfortunate,
   ungainly, ungifted, unhandy, unhappy, unintellectual,
   unintelligent, unmeet, unproficient, unprofitable, unqualified,
   unreasoning, unseasonable, unseemly, unskilled, unskillful,
   unsuitable, unsuited, untalented, unthinking, untimely, unwise,
   unworkmanlike, wacky, wet, witless, wooden, wrong