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]