The Collaborative International Dictionary of English v.0.48:

Nervousness \Nerv"ous*ness\, n.
   State or quality of being nervous.
   [1913 Webster]

WordNet (r) 3.0 (2006):

nervousness
    n 1: the anxious feeling you have when you have the jitters
         [syn: jitteriness, jumpiness, nervousness,
         restiveness]
    2: an uneasy psychological state; "he suffered an attack of
       nerves" [syn: nervousness, nerves]
    3: a sensitive or highly strung temperament

Moby Thesaurus II by Grady Ward, 1.0:

187 Moby Thesaurus words for "nervousness":
   agitability, agitation, all-overs, allergy, anaphylaxis, angst,
   anxiety, anxiety hysteria, anxiety neurosis, anxious bench,
   anxious concern, anxious seat, anxiousness, apprehension,
   apprehensiveness, bite, bitingness, bluster, bobbery, boil,
   boiling, brouhaha, bustle, cankerworm of care, care,
   chills of fear, churn, cold creeps, cold shivers, cold sweat,
   combustibility, commotion, concern, concernment, considerateness,
   conturbation, creeps, cuttingness, delicacy, discomposure,
   disorder, disquiet, disquietude, distress, disturbance, dread,
   drive, ebullition, edginess, effectiveness, embroilment,
   emotional instability, emotionalism, empathy, eruptiveness,
   excitability, excitableness, excitement, explosiveness,
   exquisiteness, fear, fear and trembling, ferment, fermentation,
   fever, feverishness, fidgets, fineness, flap, flurry, fluster,
   flutteration, foment, force, forcefulness, foreboding,
   forebodingness, fume, fuss, goose bumps, gooseflesh, guts,
   heartquake, horripilation, hubbub, hurly-burly, hyperesthesia,
   hyperpathia, hypersensitivity, identification, impressiveness,
   incisiveness, inflammability, inquietude, irascibility,
   irritability, jimjams, jitters, jumpiness, latent violence,
   maelstrom, malaise, misgiving, moil, mordancy, nerviness,
   nervosity, nervous strain, nervous tension, overanxiety,
   oversensibility, oversensitiveness, overtenderness, palpitation,
   passibility, perceptiveness, perceptivity, perturbability,
   perturbation, photophobia, pins and needles, poignancy, power,
   prickliness, pucker, punch, quaking, quiver of terror,
   responsiveness, restlessness, roil, rout, row, seethe, seething,
   sensitiveness, sensitivity, sensitization, shivers, sinew,
   sinewiness, skittishness, solicitude, soreness, startlishness,
   stew, stir, strain, strength, strong language, supersensitivity,
   suspense, sweat, swirl, sympathy, tact, tactfulness,
   tempestuousness, tenderness, tension, tetchiness, thin skin,
   thrill of fear, ticklishness, to-do, touchiness, trenchancy,
   trepidation, trepidity, trouble, tumult, tumultuation, turbidity,
   turbulence, turmoil, twitter, unease, uneasiness, unquietness,
   unrest, upset, vexation, vigor, vigorousness, violence, vitality,
   zeal