The Collaborative International Dictionary of English v.0.48:

Inapplicable \In*ap"pli*ca*ble\, a. [Pref. in- not +
   applicable.]
   Not applicable; incapable of being applied; not adapted; not
   suitable; as, the argument is inapplicable to the case. --J.
   S. Mill.

   Syn: Unsuitable; unsuited; unadapted; inappropriate;
        inapposite; irrelevant. -- In*ap"pli*ca*ble*ness, n.
        -- In*ap"pli*ca*bly, adv.
        [1913 Webster]

WordNet (r) 3.0 (2006):

inapplicable
    adj 1: not capable of being applied; "rules inapplicable to day
           students" [syn: inapplicable, unsuitable]

Moby Thesaurus II by Grady Ward, 1.0:

81 Moby Thesaurus words for "inapplicable":
   adrift, beside the mark, beside the point, beside the question,
   extraneous, extrinsic, foreign, functionless, ill-adapted,
   ill-assorted, ill-chosen, ill-fitted, ill-matched, ill-sorted,
   ill-suited, ill-timed, immaterial, impertinent, improper,
   in disrepair, inadmissible, inapposite, inappropriate, inapt,
   incidental, inconsequent, inept, infelicitous, inoperable,
   inoperative, irrelative, irrelevant, mal a propos, maladjusted,
   malapropos, misjoined, mismatched, mismated, misplaced,
   nihil ad rem, nonessential, nonfunctional, nonutilitarian,
   not at issue, off base, off the subject, otiose, out of character,
   out of joint, out of keeping, out of line, out of order,
   out of place, out of proportion, out of season, out of time,
   out of tune, out of whack, out-of-the-way, parenthetical,
   unadapted, unapt, unbecoming, unbefitting, unconducive,
   unconnected, unemployable, unessential, unfit, unfitted, unfitting,
   unhelpful, unqualified, unrelated, unseasonable, unseemly,
   unsuitable, unsuited, untimely, unusable, unworkable