The Collaborative International Dictionary of English v.0.48:

Solicitude \So*lic"i*tude\, n. [F. sollicitude,r L.
   sollicitudo.]
   The state of being solicitous; uneasiness of mind occasioned
   by fear of evil or desire good; anxiety.
   [1913 Webster]

         The many cares and great labors of worldly men, their
         solicitude and outward shows.            --Sir W.
                                                  Raleigh.
   [1913 Webster]

         The mother looked at her with fond solicitude. --G. W.
                                                  Cable.
   [1913 Webster]

   Syn: Carefulness; concern; anxiety. See Care.
        [1913 Webster]

WordNet (r) 3.0 (2006):

solicitude
    n 1: a feeling of excessive concern [syn: solicitude,
         solicitousness]

Moby Thesaurus II by Grady Ward, 1.0:

123 Moby Thesaurus words for "solicitude":
   TLC, accommodatingness, affability, agitation, agreeableness,
   alarm, all-overs, amenity, angst, anticipation, anxiety,
   anxiety hysteria, anxiety neurosis, anxious bench, anxious concern,
   anxious seat, anxiousness, apprehension, apprehensiveness,
   attention, attentiveness, calculation, cankerworm of care,
   canniness, care, careful consideration, carefulness, caution,
   cautiousness, circumspection, circumspectness, civility, comity,
   complaisance, compunction, concern, concernment, considerateness,
   consideration, courteousness, courtesy, deference,
   deliberate stages, deliberateness, deliberation, delicacy,
   discretion, disquiet, disquietude, distress, disturbance, dread,
   fear, fearfulness, foreboding, forebodingness, forethought,
   gingerliness, gracefulness, graciousness, guardedness, hedge,
   hedging, heed, heedfulness, helpfulness, hesitation, indulgence,
   inquietude, judiciousness, leniency, loving care, malaise,
   mindfulness, misgiving, nervous strain, nervous tension,
   nervousness, obligingness, overanxiety, pawkiness, perturbation,
   pins and needles, politeness, preparedness, prior consultation,
   prudence, prudentialness, pucker, qualm, regard, regardfulness,
   respect, respectfulness, safeness, safety first, scruple,
   slowness to act, solicitousness, stew, strain, suspense, tact,
   tactfulness, tender loving care, tension, tentativeness,
   thoroughness, thought, thoughtfulness, toleration, trouble,
   uncommunicativeness, unease, uneasiness, unprecipitateness,
   unquietness, upset, urbanity, vexation, watchfulness, worry,
   zeal