The Collaborative International Dictionary of English v.0.48:

Ill-timed \Ill"-timed`\, a.
   Done, attempted, or said, at an unsuitable or unpropitious
   time; occurring at an inappropriate time; as, an ill-timed
   intervention.

   Syn: ill timed(predicate), inappropriate, unseasonable,
        untimely, wrong, poorly timed, badly timed.
        [1913 Webster]

WordNet (r) 3.0 (2006):

ill-timed
    adj 1: badly timed; "an ill-timed intervention"; "you think my
           intrusion unseasonable"; "an untimely remark"; "it was
           the wrong moment for a joke" [syn: ill-timed,
           unseasonable, untimely, wrong]

Moby Thesaurus II by Grady Ward, 1.0:

80 Moby Thesaurus words for "ill-timed":
   bad, futile, ill-adapted, ill-advised, ill-assorted, ill-chosen,
   ill-considered, ill-fitted, ill-matched, ill-seasoned, ill-sorted,
   ill-suited, impolitic, improper, inadmissible, inadvisable,
   inapplicable, inapposite, inappropriate, inapt, inauspicious,
   incongruous, inconvenient, inept, inexpedient, infelicitous,
   inopportune, intempestive, intrusive, irrelevant, late,
   mal a propos, maladjusted, malapropos, misjoined, mismatched,
   mismated, misplaced, mistimed, off base, out of character,
   out of joint, out of keeping, out of line, out of phase,
   out of place, out of proportion, out of season, out of time,
   out of tune, premature, too late, too soon, unadapted, unapt,
   unbecoming, unbefitting, undesirable, unfavorable, unfit, unfitted,
   unfitting, unfortunate, unhandy, unhappy, unlucky, unmeet,
   unprofitable, unpropitious, unqualified, unready, unripe,
   unseasonable, unseemly, unsuitable, unsuited, untimely, untoward,
   unwise, wrong