The Collaborative International Dictionary of English v.0.48:

Heraldry \Her"ald*ry\, n.
   1. The art or office of a herald; the art, practice, or
      science of recording genealogies, and blazoning arms or
      ensigns armorial; also, of marshaling cavalcades,
      processions, and public ceremonies.
      [1913 Webster]

   2. A coat of arms or some other heraldic device or collection
      of heraldic symbols.
      [PJC]

WordNet (r) 3.0 (2006):

heraldry
    n 1: the study and classification of armorial bearings and the
         tracing of genealogies
    2: emblem indicating the right of a person to bear arms

Moby Thesaurus II by Grady Ward, 1.0:

56 Moby Thesaurus words for "heraldry":
   armory, badge, badge of office, badges, baton, blazonry, brassard,
   button, cap and gown, chain, chain of office, circumstance,
   class ring, cockade, collar, cross, decoration, dress, eagle,
   emblems, ensigns, fasces, figurehead, fleur-de-lis, formality,
   hammer and sickle, insignia, lapel pin, livery, mace, mantle,
   markings, medal, mortarboard, old school tie, pin, pomp, pride,
   regalia, ring, rose, school ring, shamrock, sigillography,
   skull and crossbones, solemnity, sphragistics, staff, state,
   swastika, tartan, thistle, tie, uniform, verge, wand



Bouvier's Law Dictionary, Revised 6th Ed (1856):

HERALDRY, civil and canon law. The art or office of a herald. It is the art,
practice, or science of recording genealogies, and blazoning arms or ensigns
armorial. It also teaches whatever relates to the marshaling of cavalcades,
processions, and other public ceremonies. Encyc.; Ridley's View of the Civil
and Canon Law, pt. 2, c. 1, Sec. 6.