The Collaborative International Dictionary of English v.0.48:

Prepared \Pre*pared"\, a.
   Made fit or suitable; adapted; ready; as, prepared food;
   prepared questions. -- Pre*par"ed*ly, adv. --Shak. --
   Pre*par"ed*ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

prepared
    adj 1: made ready or fit or suitable beforehand; "a prepared
           statement"; "be prepared for emergencies" [ant:
           unprepared]
    2: having made preparations; "prepared to take risks" [syn:
       disposed(p), fain, inclined(p), prepared]
    3: equipped or prepared with necessary intellectual resources;
       "graduates well equipped to handle such problems"; "equipped
       to be a scholar"

Moby Thesaurus II by Grady Ward, 1.0:

122 Moby Thesaurus words for "prepared":
   able, accomplished, accoutered, advance, agape, agog, all agog,
   all ready, all set, anticipant, anticipating, anticipative,
   anticipatory, armed, armed and ready, at concert pitch, awaiting,
   booted and spurred, briefed, career, catered, certain, changed,
   clairvoyant, coached, cocked, confident, convenience, conversant,
   disposed, divinatory, eager, endowed, equipped, expectant,
   expecting, familiarized, farseeing, farsighted, finished, fitted,
   fitted out, forearmed, forehanded, foreknowing, foreseeing,
   foresighted, forestalling, forethoughted, forethoughtful,
   forewarned, furnished, gaping, good and ready, groomed, heeled,
   hopeful, in anticipation, in arms, in battle array, in expectation,
   in readiness, in the saddle, inclined, informed, initiate,
   initiated, instant, intuitive, invested, loaded, loaded for bear,
   longsighted, looking for, looking forward to, mature, mobilized,
   modified, not surprised, on the mark, optimistic, outfitted,
   planned, practiced, prearranged, precognitive, precognizant,
   predisposed, prepared and ready, prepped, prescient, primed,
   processed, professional, provided, provident, providential,
   prudent, psyched up, purveyed, ready, ready for anything,
   ready-made, rigged, ripe, sagacious, sanguine, set, skilled,
   supplied, sure, technical, trained, treated, unsurprised,
   up in arms, vigilant, waiting, waiting for, watching for,
   well-prepared, willing