The Collaborative International Dictionary of English v.0.48:

Softness \Soft"ness\, n. [AS. s?ftness, s?ftnyss.]
   The quality or state of being soft; -- opposed to hardness,
   and used in the various specific senses of the adjective.
   [1913 Webster] Soft-shell

WordNet (r) 3.0 (2006):

softness
    n 1: the property of giving little resistance to pressure and
         being easily cut or molded [ant: hardness]
    2: poor physical condition; being out of shape or out of
       condition (as from a life of ease and luxury) [syn:
       unfitness, softness] [ant: fitness, physical fitness]
    3: the quality of weather that is deliciously mild and soothing;
       "the day's heat faded into balminess"; "the climate had the
       softness of the south of France" [syn: balminess,
       softness]
    4: a state of declining economic condition; "orders have
       recently picked up after a period of extreme softness"; "he
       attributes the disappointing results to softness in the
       economy"
    5: a sound property that is free from loudness or stridency;
       "and in softness almost beyond hearing" [ant: intensity,
       loudness, volume]
    6: a visual property that is subdued and free from brilliance or
       glare; "the softness of the morning sky"
    7: acting in a manner that is gentle and mild and even-tempered;
       "his fingers have learned gentleness"; "suddenly her gigantic
       power melted into softness for the baby"; "even in the pulpit
       there are moments when mildness of manner is not enough"
       [syn: gentleness, softness, mildness]
    8: the quality of being indistinct and without sharp outlines
       [syn: indistinctness, softness, blurriness,
       fogginess, fuzziness] [ant: distinctness, sharpness]
    9: the trait of being effeminate (derogatory of a man); "the
       students associated science with masculinity and arts with
       effeminacy"; "Spartans accused Athenians of effeminateness";
       "he was shocked by the softness of the atmosphere surrounding
       the young prince, arising from the superfluity of the
       femininity that guided him" [syn: effeminacy,
       effeminateness, sissiness, softness, womanishness,
       unmanliness]
    10: a disposition to be lenient in judging others; "softness is
        not something permitted of good leaders"

Moby Thesaurus II by Grady Ward, 1.0:

194 Moby Thesaurus words for "softness":
   acceptance, adynamia, airiness, anemia, ascent, atony,
   blah feeling, bloodlessness, bubbliness, buoyancy, cachexia,
   cachexy, carelessness, chicken-liveredness, chickenheartedness,
   clemency, clementness, commodiousness, compassion, convenience,
   cowardice, cowardliness, coziness, cullibility, cushioniness,
   daintiness, debilitation, debility, deceivability, decrescendo,
   delicacy, dimness, doughiness, down, downiness, dullness,
   dupability, easiness, easygoingness, ethereality, etiolation,
   faintheart, faintheartedness, faintness, fatigue, fear,
   feeblemindedness, feebleness, filminess, fine-grainedness,
   fineness, flabbiness, flaccidity, flatness, fleshiness,
   floatability, fluff, fluffiness, foaminess, fondness, forbearance,
   forbearing, forcelessness, friendliness, frothiness, fuzz,
   fuzziness, gentleness, gossameriness, greenness, gullibility,
   henheartedness, hoaxability, homelikeness, homeliness, homeyness,
   hospitality, humaneness, humanity, impotence, impotency,
   imprecision, impuissance, indifference, indistinctness, infirmity,
   ingenuousness, lack of weight, languishment, languor, lassitude,
   laxity, laxness, lenience, leniency, lenientness, lenity,
   levitation, levity, lightness, lily-liveredness, listlessness,
   looseness, loosening, lowness, luxuriousness, mashiness,
   mercifulness, mercy, mildness, milksopism, milksoppiness,
   milksoppishness, moderateness, mushiness, naiveness, naivete,
   naivety, negligence, overindulgence, overpermissiveness, pastel,
   pastel color, pastiness, patience, peace, peacefulness, peach fuzz,
   permissiveness, persuadability, pigeonheartedness, pithiness, pity,
   power vacuum, powerlessness, prostration, pubescence, pulpiness,
   pulpousness, refinement, relaxation, relaxedness, remissness,
   reposefulness, restfulness, roominess, satin, satininess,
   seduceability, silk, silkiness, simpleness, simplicity, slackness,
   sloppiness, sluggishness, smoothness, snugness, soft color,
   softheartedness, sponginess, squashiness, strengthlessness,
   subaudibility, subduedness, subtle color, succulence,
   tender feeling, tenderheartedness, tenderness, timidity, timidness,
   timorousness, tolerance, unclearness, unheaviness, unmanfulness,
   unmanliness, unrestraint, unsophistication, velvet, velvetiness,
   volatility, warm heart, warmheartedness, warmness, weak-mindedness,
   weakheartedness, weakliness, weakness, weariness, weightlessness,
   yeastiness, yellowness