The Collaborative International Dictionary of English v.0.48:

Readiness \Read"i*ness\, n.
   The state or quality of being ready; preparation; promptness;
   aptitude; willingness.
   [1913 Webster]

         They received the word with all readiness of mind.
                                                  --Acts xvii.
                                                  11.
   [1913 Webster]

   Syn: Facility; quickness; expedition; promptitude;
        promptness; aptitude; aptness; knack; skill; expertness;
        dexterity; ease; cheerfulness. See Facility.
        [1913 Webster]

WordNet (r) 3.0 (2006):

readiness
    n 1: the state of having been made ready or prepared for use or
         action (especially military action); "putting them in
         readiness"; "their preparation was more than adequate"
         [syn: readiness, preparedness, preparation]
    2: prompt willingness; "readiness to continue discussions";
       "they showed no eagerness to spread the gospel"; "they
       disliked his zeal in demonstrating his superiority"; "he
       tried to explain his forwardness in battle" [syn:
       readiness, eagerness, zeal, forwardness]
    3: (psychology) being temporarily ready to respond in a
       particular way; "the subjects' set led them to solve problems
       the familiar way and to overlook the simpler solution"; "his
       instructions deliberately gave them the wrong set" [syn:
       set, readiness]
    4: a natural effortlessness; "they conversed with great
       facility"; "a happy readiness of conversation"--Jane Austen
       [syn: facility, readiness]

Moby Thesaurus II by Grady Ward, 1.0:

305 Moby Thesaurus words for "readiness":
   Italian hand, OK, a thing for, ability, acceptance, accord,
   acquiescence, acuity, acuteness, address, adeptness, adroitness,
   affirmative, affirmative voice, agility, agreeability,
   agreeableness, agreement, airmanship, alacrity, alertness,
   amenability, animation, anticipation, anxiety, anxiousness,
   appetite, approbation, approval, aptitude, aptness, ardor, art,
   artfulness, artifice, artisanship, artistry, assent, astuteness,
   attention, attentiveness, avidity, avidness, aye, beginnings, bent,
   bias, blessing, bravura, breathless impatience, brightness,
   brilliance, briskness, cageyness, callidity, canniness, capability,
   capacity, cast, cheerful consent, cheerful readiness, cheerfulness,
   cleverness, command, competence, competency, compliance, conatus,
   condition, conduciveness, connivance, consent, contemplation,
   control, cooperativeness, coordination, craft, craftiness,
   craftsmanship, cunning, cunningness, decisiveness, deftness,
   delight, dexterity, dexterousness, dextrousness, diathesis,
   diplomacy, discretion, dispatch, disposition, docility, eagerness,
   earliness, early hour, early stage, ease, educability, efficiency,
   elan, eloquence, endorsement, enthusiasm, envisagement,
   envisionment, expedition, expeditiousness, expertise, expertness,
   facility, farseeingness, farsightedness, favorable disposition,
   favorableness, feeling for, fine Italian hand, finesse,
   first crack, first stage, fitness, fittedness, fluency, forecast,
   foreglance, foregleam, foreglimpse, forehandedness, foreseeing,
   foresight, foresightedness, forwardness, foxiness, gameness,
   gamesmanship, goodwill, grace, graciousness, grip, ground floor,
   guile, gust, gusto, handiness, head start, horsemanship, immediacy,
   immediateness, impatience, impressionability, in readiness,
   inclination, ingeniousness, ingenuity, insidiousness,
   instantaneousness, intelligence, inventiveness, keen desire,
   keenness, know-how, leaning, liability, life, liking, liveliness,
   longsightedness, looking ahead, malleability, marksmanship,
   mastership, mastery, maturity, moldability, motivation, nimbleness,
   okay, one-upmanship, penchant, permission, plasticity, pliability,
   pliancy, practical ability, prediction, predilection,
   predisposition, prejudice, preparation, preparedness,
   prepublication, prevenience, preview, prevision, probability,
   proclivity, proficiency, promptitude, promptness, proneness,
   propensity, prospect, prospection, providence, provision, prowess,
   prudence, punctuality, punctualness, qualification, quickness,
   rapidity, ratification, ready, receptive mood, receptiveness,
   receptivity, resource, resourcefulness, responsiveness, right mood,
   ripeness, running start, sagacity, sanction, satanic cunning,
   savoir-faire, savvy, seamanship, seasoning, sensitivity to,
   sharpness, shiftiness, shrewdness, skill, skillfulness,
   sleeplessness, sleight, slipperiness, slyness, smartness,
   sneakiness, soft spot, sophistry, speediness, spirit, spryness,
   stealth, stealthiness, style, submission, subtilty, subtleness,
   subtlety, suitability, suitableness, suitedness, summariness,
   suppleness, susceptibility, swiftness, tact, tactfulness,
   teachability, teachableness, technical brilliance,
   technical mastery, technical skill, technique, tempering, tendency,
   time to spare, timing, tractability, trainableness, trickiness,
   trim, tropism, turn, twist, ungrudgingness, unloathness,
   unreluctance, verve, very beginning, virtuosity, vitality,
   vivacity, volubility, wakefulness, wariness, warp, weakness, wiles,
   wiliness, willing ear, willing heart, willingness, wit, wizardry,
   workmanship, zeal, zealousness, zest, zestfulness