The Collaborative International Dictionary of English v.0.48:

Warmth \Warmth\, n.
   1. The quality or state of being warm; gentle heat; as, the
      warmth of the sun; the warmth of the blood; vital warmth.
      [1913 Webster]

            Here kindly warmth their mounting juice ferments.
                                                  --Addison.
      [1913 Webster]

   2. A state of lively and excited interest; zeal; ardor;
      fervor; passion; enthusiasm; earnestness; as, the warmth
      of love or piety; he replied with much warmth. "Spiritual
      warmth, and holy fires." --Jer. Taylor.
      [1913 Webster]

            That warmth . . . which agrees with Christian zeal.
                                                  --Sprat.
      [1913 Webster]

   3. (Paint.) The glowing effect which arises from the use of
      warm colors; hence, any similar appearance or effect in a
      painting, or work of color.
      [1913 Webster]

   Syn: Zeal; ardor; fervor; fervency; heat; glow; earnestness;
        cordiality; animation; eagerness; excitement; vehemence.
        [1913 Webster]

WordNet (r) 3.0 (2006):

warmth
    n 1: the sensation caused by heat energy [syn: heat, warmth]
    2: a warmhearted feeling [syn: warmheartedness, warmth]
    3: the quality of having a moderate degree of heat; "an
       agreeable warmth in the house" [syn: warmth, warmness]
    4: the trait of being intensely emotional [syn: heat,
       warmth, passion]
    5: a quality proceeding from feelings of affection or love [syn:
       affectionateness, fondness, lovingness, warmth]

Moby Thesaurus II by Grady Ward, 1.0:

137 Moby Thesaurus words for "warmth":
   abandon, activity, affectionateness, amiability, animal heat,
   animation, ardency, ardor, benignancy, benignity, blood heat,
   blush, body heat, bonhomie, brio, briskness, brotherhood, burning,
   calidity, caloric, coal heat, commitment, committedness,
   compassion, convected heat, cordiality, dedication, devotedness,
   devotion, devoutness, earnestness, ecstasy, elan, electric heat,
   enthusiasm, excitement, faith, faithfulness, feeling of kinship,
   fellow feeling, fervency, fervidness, fervor, fever, fever heat,
   fidelity, fieriness, fire, flush, fraternal feeling, friendliness,
   furor, fury, gas heat, generosity, geniality, glow, goodness,
   goodness of heart, graciousness, gusto, healthy glow, heart,
   heart of gold, heartiness, heat, heatedness, heating,
   hospitableness, hospitality, hot-air heat, hotness, humaneness,
   humanity, hypothermia, impassionedness, impetuosity, impetus,
   incalescence, induction heat, intensity, intentness, joie de vivre,
   kindheartedness, kindliness, kindly disposition, kindness,
   liberality, life, liveliness, loving kindness, loyalty, lustiness,
   mettle, molecular heat, neighborliness, niceness, oil heat,
   open door, openheartedness, passion, passionateness, perkiness,
   pertness, radiant heat, receptiveness, relish, resolution,
   robustness, savor, seriousness, sincerity, softheartedness,
   solar heat, soul, soul of kindness, spirit, spiritedness,
   steam heat, superheat, superheatedness, sympathy,
   tenderheartedness, thermal radiation, ultraviolet heat, vehemence,
   verve, vivacity, warm color, warmheartedness, warmness,
   warmth of color, warmth of feeling, warmth of heart, zeal, zest,
   zestfulness