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]