ataraxy

Ataraxia \At`a*rax"i*a\, Ataraxy \At"a*rax`y\, n. [NL. ataraxia,
   Gr. 'ataraxi`a; 'a priv. + tarakto`s disturbed, tara`ssein to
   disturb.]
   Perfect peace of mind, or calmness.
   [1913 Webster]
    

117 Moby Thesaurus words for "ataraxy":
      accidia, acedia, aloofness, apathy, ataraxia, benumbedness, blah,
      blahs, bovinity, calmness, carelessness, casualness, comatoseness,
      composure, contemplation, coolness, detachment, disinterest,
      dispassion, dispassionateness, disregard, disregardfulness,
      dullness, easy temper, easygoingness, even temper, good temper,
      heartlessness, hebetude, heedlessness, hopelessness, impassiveness,
      impassivity, imperturbability, imperturbableness, inappetence,
      inattention, incuriosity, indifference, indiscrimination,
      inexcitability, inexcitableness, inirritability, insouciance,
      lack of affect, lack of appetite, lackadaisicalness, languidness,
      lethargicalness, lethargy, listlessness, lucid stillness,
      marmoreal repose, mindlessness, negligence, nirvana, nonchalance,
      numbness, passiveness, passivity, patience, peace, peacefulness,
      phlegm, phlegmaticalness, phlegmaticness, placidity, placidness,
      plucklessness, pococurantism, quiescence, quiescency, quiet,
      quietism, quietness, quietude, recklessness, regardlessness,
      repose, resignation, resignedness, rest, restfulness, sangfroid,
      satori, serenity, silence, silken repose, sleep, sloth,
      sluggishness, slumber, smooth temper, sopor, soporifousness,
      spiritlessness, spunklessness, steadiness, stillness, stoicism,
      stolidity, stupefaction, stupor, supineness, torpidity, torpidness,
      torpor, tranquillity, unanxiousness, unconcern, unirritableness,
      unmindfulness, unnervousness, unpassionateness, unsolicitousness,
      wise passiveness, withdrawnness