Os"si*cle (?), n. [L. ossiculum, dim. of os, ossis, a bone.] 1. A little bone; as, the auditory ossicles in the tympanum of the ear.

2. (Zoöl.) One of numerous small calcareous structures forming the skeleton of certain echinoderms, as the starfishes.

• (anatomy) A small bone (or bony structure), especially one of the three of the middle ear.
       The incus is one of the three auditory ossicles.
       Quotations
       *1836: The eyeballs were surrounded by a ring of bones, the sclerotic ossicle, which probably protected their eyes when diving abruptly for prey. — William Buckland, Geology and Mineralogy, Considered with Reference to Natural Theology, vol. 1, William Pickering, 1836, p. 174
  
• (zoology) Bone-like joint or plate, especially:
       * one of numerous small calcareous structures forming the skeleton of certain echinoderms, as the starfishes;
       * one of the hard articuli or joints of the stem or branches of a crinoid or encrinite;
       * one of the several small hard chitinous parts or processes of the gastric skeleton of crustaceans, as in the stomach of a lobster or crawfish.
       The skeleton of echinoderms is made of ossicles, linked to each other via muscles and connective tissue.