The Collaborative International Dictionary of English v.0.48:

Fullness \Full"ness\, n.
   The state of being full, or of abounding; abundance;
   completeness. [Written also fulness.]
   [1913 Webster]

         "In thy presence is fullness of joy."    --Ps. xvi. 11.
   [1913 Webster]

WordNet (r) 3.0 (2006):

fullness
    n 1: completeness over a broad scope [syn: comprehensiveness,
         fullness]
    2: the property of a sensation that is rich and pleasing; "the
       music had a fullness that echoed through the hall"; "the
       cheap wine had no body, no mellowness"; "he was well aware of
       the richness of his own appearance" [syn: fullness,
       mellowness, richness]
    3: the condition of being filled to capacity [ant: emptiness]
    4: greatness of volume [syn: fullness, voluminosity,
       voluminousness]

Moby Thesaurus II by Grady Ward, 1.0:

184 Moby Thesaurus words for "fullness":
   abundance, affluence, ample sufficiency, ampleness, amplitude,
   avalanche, bassness, beam, bellyful, bonanza, boundlessness,
   bountifulness, bountiousness, breadth, broadness, bulk,
   bumper crop, ceaselessness, completeness, comprehensiveness,
   congestion, consecutiveness, constancy, constant flow,
   continualness, continuity, continuousness, copiousness, crescendo,
   deepness, distance across, endlessness, engorgement, enormity,
   enormousness, entireness, equilibrium, exhaustiveness, expanse,
   extent, extravagance, exuberance, featurelessness, fertility, fill,
   flood, flood tide, flow, foison, formidableness, full,
   full measure, gaplessness, generosity, generousness, gigantism,
   glut, grandeur, grandness, great abundance, great plenty,
   great scope, greatness, gush, high tide, high water, holism,
   hollowness, hugeness, immensity, impletion, incessancy,
   inclusiveness, infinity, intactness, integrity, intensity,
   jointlessness, landslide, largeness, latitude, lavishness,
   liberality, liberalness, lots, loudishness, loudness, lowness,
   luxuriance, magnitude, maximum, mellowness, might, mightiness,
   monotony, more than enough, much, muchness, myriad, myriads,
   numerousness, opulence, opulency, outpouring, overflow,
   overfullness, plangency, plenitude, plenteousness, plentifulness,
   plenty, plethora, power, prevalence, prodigality, prodigiousness,
   productiveness, profuseness, profusion, quantities, repleteness,
   repletion, resonance, rich harvest, rich vein, richness, riot,
   riotousness, satiation, satiety, satisfaction, saturatedness,
   saturation, saturation point, scads, scope, seamlessness, shower,
   skinful, smoothness, snootful, sonority, sonorousness, soundness,
   span, spate, spread, spring tide, stability, steadiness,
   steady state, stream, strength, stupendousness, substantiality,
   substantialness, successiveness, superabundance, supersaturation,
   surfeit, surge, surge of sound, swell, swelling, teemingness,
   total approach, totality, tremendousness, unbrokenness,
   undifferentiation, uniformity, unintermittedness,
   uninterruptedness, uninterruption, unity, universality,
   unrelievedness, vastness, vibrancy, volume, wealth, wholeness,
   wideness, width