The Collaborative International Dictionary of English v.0.48:

Generosity \Gen`er*os"i*ty\, n. [L. generositas: cf. F.
   g['e]n['e]rosit['e].]
   1. Noble birth. [Obs.] --Harris (Voyages).
      [1913 Webster]

   2. The quality of being noble; noble-mindedness.
      [1913 Webster]

            Generosity is in nothing more seen than in a candid
            estimation of other men's virtues and good
            qualities.                            --Barrow.
      [1913 Webster]

   3. Liberality in giving; munificence.

   Syn: Magnanimity; liberality.
        [1913 Webster]

WordNet (r) 3.0 (2006):

generosity
    n 1: the trait of being willing to give your money or time [syn:
         generosity, generousness] [ant: stinginess]
    2: acting generously [syn: generosity, unselfishness]

Moby Thesaurus II by Grady Ward, 1.0:

150 Moby Thesaurus words for "generosity":
   BOMFOG, Benthamism, Christian charity, Christian love, abundance,
   affluence, agape, altruism, amiability, ample sufficiency,
   ampleness, amplitude, avalanche, beneficence, benevolence,
   benevolent disposition, benevolentness, bigheartedness, bigness,
   bonanza, bonhomie, bounteousness, bountifulness, bountiousness,
   bounty, brotherly love, bumper crop, caritas, charitableness,
   charity, chivalrousness, chivalry, copiousness, cordiality,
   do-goodism, easy purse strings, elevation, errantry, exaltation,
   extravagance, exuberance, fertility, flood, flow, flower power,
   foison, free hand, freedom, freehandedness, freeheartedness,
   freeness, friendliness, full measure, fullness, generousness,
   geniality, giving, givingness, goodwill, grace, graciousness,
   great abundance, great heart, great plenty, greatheartedness,
   greatness, greatness of heart, gush, heartiness, heroism,
   high-mindedness, hospitableness, hospitality, humanitarianism,
   idealism, knight-errantry, knightliness, landslide,
   largeheartedness, largeness, largess, lavishness, liberality,
   liberalness, loftiness, lots, love, love of mankind, luxuriance,
   magnanimity, magnanimousness, maximum, more than enough, much,
   munificence, myriad, myriads, neighborliness, nobility,
   noble-mindedness, nobleness, numerousness, open door, open hand,
   open heart, openhandedness, openheartedness, opulence, opulency,
   outpouring, overflow, philanthropism, philanthropy, plenitude,
   plenteousness, plentifulness, plenty, prevalence, princeliness,
   prodigality, productiveness, profuseness, profusion, quantities,
   receptiveness, repleteness, repletion, rich harvest, rich vein,
   richness, riot, riotousness, scads, shower, spate, stream,
   sublimity, substantiality, substantialness, superabundance,
   teemingness, unselfishness, utilitarianism, warmheartedness,
   warmness, warmth, wealth, welcome, welfarism, well-disposedness