The Collaborative International Dictionary of English v.0.48:

Headdress \Head"dress`\ (h[e^]d"dr[e^]s`), n.
   1. A covering or ornament for the head; a headtire; as,
      chiefs among the plains Indians had elaborate long
      headdresses with many feathers.
      [1913 Webster]

            Among birds the males very often appear in a most
            beautiful headdress, whether it be a crest, a comb,
            a tuft of feathers, or a natural little plume.
                                                  --Addison.
      [1913 Webster]

   2. A manner of dressing the hair or of adorning it, whether
      with or without a veil, ribbons, combs, etc.
      [1913 Webster]

WordNet (r) 3.0 (2006):

headdress
    n 1: clothing for the head [syn: headdress, headgear]