The Collaborative International Dictionary of English v.0.48:

Unready \Un*read"y\, a.
   1. Not ready or prepared; not prompt; slow; awkward; clumsy.
      --Dryden.
      [1913 Webster]

            Nor need the unready virgin strike her breast.
                                                  --Keble.
      [1913 Webster]

   2. Not dressed; undressed. [Obs.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Unready \Un*read"y\, v. t. [1st pref. un- + ready.]
   To undress. [Obs.] --Sir P. Sidney.
   [1913 Webster]

WordNet (r) 3.0 (2006):

unready
    adj 1: not prepared or in a state of readiness; slow to
           understand or respond; "she cursed her unready tongue"
           [ant: ready]

Moby Thesaurus II by Grady Ward, 1.0:

154 Moby Thesaurus words for "unready":
   ad-lib, airy, arrested, asleep, back, backward, behindhand,
   belated, blocked, careless, casual, caught napping,
   caught off balance, caught short, cursory, degage, delayed,
   delayed-action, detained, disregardant, disregardful, easygoing,
   extemporaneous, extemporized, flippant, forgetful, free and easy,
   goofing off, haphazard, hasty, heedless, held up, hung up,
   ill-considered, ill-seasoned, ill-timed, impromptu, improper,
   improvised, in a bind, in abeyance, inappropriate, inauspicious,
   incautious, inconsiderate, inconvenient, indifferent, inexpectant,
   inexpedient, infelicitous, inopportune, insouciant, intempestive,
   intrusive, irrelevant, jammed, late, latish, lazy, makeshift,
   mal a propos, malapropos, mistimed, moratory, napping,
   never on time, nodding, nonexpectant, oblivious, obstructed,
   off base, off-guard, offhand, out of line, out of phase,
   out of time, overdue, perfunctory, precipitate, premature,
   reckless, regardless, respectless, retarded, rough-and-ready,
   sleeping, slow, snap, stopped, surprised, tactless, taken aback,
   taken by surprise, taken unawares, tardy, thoughtless, too late,
   too soon, tripped up, unadmonished, unadvised, unalert,
   unanticipating, unanticipative, unarranged, unaware, unbefitting,
   unbegun, uncautious, unconcocted, uncontrived, undeliberated,
   undevised, undiplomatic, unexpecting, unfavorable, unfit,
   unfitting, unforewarned, unfortunate, unguarded, unguessing,
   unhandy, unhappy, unhatched, unheedful, unheeding, uninformed,
   unlucky, unmade, unmanufactured, unmindful, unorganized, unplanned,
   unpremeditated, unprepared, unprimed, unpropitious, unpunctual,
   unripe, unseasonable, unsolicitous, unstudied, unsuitable,
   unsuspecting, untactful, unthinking, untimely, untoward,
   unvigilant, unwarned, unwary, unwatchful, wrong