WordNet (r) 3.0 (2006):

eeriness
    n 1: strangeness by virtue of being mysterious and inspiring
         fear [syn: eeriness, ghostliness]

Moby Thesaurus II by Grady Ward, 1.0:

67 Moby Thesaurus words for "eeriness":
   Hippocratic face, alarmingness, appallingness, awfulness,
   cadaverousness, corpselikeness, creepiness, deadliness,
   deathlikeness, deathliness, direness, disconcertingness,
   dismayingness, disquietingness, dreadfulness, elfdom,
   facies Hippocratica, faerie, fearfulness, fearsomeness,
   frighteningness, frightfulness, ghastliness, ghostlikeness,
   ghostliness, ghoulishness, grimness, grisliness, gruesomeness,
   haggardness, hideousness, horribleness, luridness, macabreness,
   mask of death, miraculousness, mysteriousness, mystery,
   numinousness, otherworldliness, paleness, pallor, preternaturalism,
   scariness, spookiness, startlingness, superhumanity,
   supernaturalism, supernaturality, supernaturalness, supernature,
   supernormalness, superphysicalness, supersensibleness,
   supranaturalism, supranature, terribleness, the occult,
   the supernatural, the supersensible, transcendentalism,
   uncanniness, unearthliness, unworldliness, wanness, weirdness,
   witchery