Source : Webster's Revised Unabridged Dictionary (1913)

Sternum \Ster"num\, n.; pl. L. {Sterna}, E. {Sternums}. [NL.,
   from Gr. ?, the breast, chest.]
   1. (Anat.) A plate of cartilage, or a series of bony or
      cartilaginous plates or segments, in the median line of
      the pectoral skeleton of most vertebrates above fishes;
      the breastbone.

   Note: The sternum is connected with the ribs or the pectorial
         girdle, or with both. In man it is a flat bone, broad
         anteriorly, narrowed behind, and connected with the
         clavicles and the cartilages of the seven anterior
         pairs of ribs. In most birds it has a high median keel
         for the attachment of the muscles of the wings.

   2. (Zo["o]l.) The ventral part of any one of the somites of
      an arthropod.

Source : WordNet®

Sterna
     n : a genus of Sterninae [syn: {genus Sterna}]