WordNet (r) 3.0 (2006):

sissiness
    n 1: the trait of being effeminate (derogatory of a man); "the
         students associated science with masculinity and arts with
         effeminacy"; "Spartans accused Athenians of
         effeminateness"; "he was shocked by the softness of the
         atmosphere surrounding the young prince, arising from the
         superfluity of the femininity that guided him" [syn:
         effeminacy, effeminateness, sissiness, softness,
         womanishness, unmanliness]