The Collaborative International Dictionary of English v.0.48:

Strangeness \Strange"ness\, n.
   The state or quality of being strange (in any sense of the
   adjective).
   [1913 Webster]

WordNet (r) 3.0 (2006):

strangeness
    n 1: unusualness as a consequence of not being well known [syn:
         unfamiliarity, strangeness] [ant: familiarity]
    2: (physics) one of the six flavors of quark
    3: the quality of being alien or not native; "the strangeness of
       a foreigner" [syn: foreignness, strangeness,
       curiousness] [ant: nativeness]

Moby Thesaurus II by Grady Ward, 1.0:

159 Moby Thesaurus words for "strangeness":
   Kern, NMR, aberration, abnormality, absurdity, alienation,
   alpha particle, anomaly, antibaryon, anticness, antilepton,
   antimeson, atomic nucleus, atomic particle, baryon, beta particle,
   bizarreness, bizarrerie, brain damage, brainsickness,
   brand-newness, callowness, clouded mind, conceit, crackpotism,
   crank, crankiness, crankism, craziness, crotchet, crotchetiness,
   curiousness, daftness, deformity, dementedness, dementia,
   derangement, deviancy, deviation, dewiness, differentness,
   disorientation, distraction, divergence, dottiness, eccentricity,
   electron, elementary particle, erraticism, erraticness,
   fantasticality, folie, freakiness, freakishness, freshness, furor,
   gloss of novelty, greenness, grotesqueness, grotesquerie,
   idiocrasy, idiosyncrasy, immaturity, insaneness, insanity,
   intactness, irrationality, irregularity, kink, lateness, lepton,
   loss of mind, loss of reason, lunacy, madness, maggot, maidenhood,
   malformation, mania, mannerism, mental deficiency,
   mental derangement, mental disease, mental disorder,
   mental disturbance, mental illness, mental instability,
   mental sickness, meson, mind overthrown, mindsickness,
   mint condition, monstrosity, monstrousness, neutron, newbornness,
   newfangledness, newfangleness, newness, nonconformity, novelness,
   novelty, nowness, nuclear force, nuclear magnetic resonance,
   nuclear particle, nuclear resonance, nucleon, nucleosynthesis,
   nucleus, oddity, oddness, originality, outlandishness, peculiarity,
   photon, pixilation, possession, presentness, pristineness, proton,
   quaintness, queerness, quip, quirk, quirkiness, rabidness, rawness,
   reasonlessness, recency, recentness, senselessness, shattered mind,
   sick mind, sickness, singularity, strong interaction, teratism,
   trick, triton, twist, unbalance, unbalanced mind, uncommonness,
   unconventionality, unfamiliarity, unnaturalness, unsaneness,
   unsound mind, unsoundness, unsoundness of mind, unusualness,
   valence electron, virginity, weirdness, whim, whimsicality, whimsy,
   witlessness