Source : Webster's Revised Unabridged Dictionary (1913)

Armilla \Ar*mil"la\, n.; pl. E. {Armillas}, L. {Armill[ae]}.
   [L., a bracelet.]
   1. An armil.

   2. (Zo["o]l.) A ring of hair or feathers on the legs.

Source : WordNet®

armilla
     n 1: a celestial globe consisting of metal hoops; used by early
          astronomers to determine the positions of stars [syn: {armillary
          sphere}]
     2: (archeology) a bracelet worn around the wrist or arm