NOUN (2)

1. myths collectively; the body of stories associated with a culture or institution or person;

2. the study of myths;

The Collaborative International Dictionary of English v.0.48:

Mythology \My*thol"o*gy\, n.; pl. Mythologies. [F. mythologie,
   L. mythologia, Gr. myqologi`a; my^qos, fable, myth + lo`gos
   speech, discourse.]
   1. The science which treats of myths; a treatise on myths.
      [1913 Webster]

   2. A body of myths; esp., the collective myths which describe
      the gods of a heathen people; as, the mythology of the
      Greeks.
      [1913 Webster]

WordNet (r) 3.0 (2006):

mythology
    n 1: myths collectively; the body of stories associated with a
         culture or institution or person
    2: the study of myths

Moby Thesaurus II by Grady Ward, 1.0:

58 Moby Thesaurus words for "mythology":
   Marchen, Mishnah, Spiritus Mundi, Sunna, Talmud, Western,
   Western story, Westerner, adventure story, allegory,
   ancient wisdom, apologue, archetypal myth, archetypal pattern,
   bedtime story, common law, custom, detective story, fable, fabliau,
   fairy lore, fairy tale, fairyism, fantasy, fiction, folk motif,
   folk story, folklore, folktale, gest, ghost story, horse opera,
   immemorial usage, legend, lore, love story, mystery, mystery story,
   myth, mythical lore, mythicism, mythos, nursery tale, parable,
   racial memory, romance, science fiction, shocker, space fiction,
   space opera, stories, suspense story, thriller, tradition,
   traditionalism, traditionality, whodunit, work of fiction



The Devil's Dictionary (1881-1906):

MYTHOLOGY, n.  The body of a primitive people's beliefs concerning its
origin, early history, heroes, deities and so forth, as distinguished
from the true accounts which it invents later.