WordNet (r) 3.0 (2006):

empathy
    n 1: understanding and entering into another's feelings

Moby Thesaurus II by Grady Ward, 1.0:

105 Moby Thesaurus words for "empathy":
   accent, accentuation, accord, accordance, affinity, agape,
   agreement, allergy, amity, anaphylaxis, appreciation, attention,
   bonds of harmony, brotherly love, caring, caritas,
   cement of friendship, charity, chord, communion, community,
   community of interests, compassion, compatibility, comprehension,
   concern, concord, concordance, congeniality, considerateness,
   correspondence, delicacy, echo, emphasis, esprit, esprit de corps,
   exquisiteness, feeling of identity, fellow feeling, fellowship,
   fineness, force, frictionlessness, good vibes, good vibrations,
   happy family, harmony, hyperesthesia, hyperpathia,
   hypersensitivity, identification, identity, insistence,
   involvement, irritability, kinship, like-mindedness, love,
   mutuality, nervousness, oneness, oversensibility,
   oversensitiveness, overtenderness, passibility, pathos, peace,
   perceptiveness, perceptivity, photophobia, prickliness, rapport,
   rapprochement, reciprocity, relating, response, responsiveness,
   sensitiveness, sensitivity, sensitization, sharing, solidarity,
   soreness, stress, supersensitivity, sympathetic chord,
   sympathetic response, sympathy, symphony, tact, tactfulness,
   team spirit, tenderness, tetchiness, thin skin, ticklishness,
   touchiness, understanding, union, unison, unity, vibes, vibrations,
   warmth, weight