calamus

noun6

1. •
   A quill; the hard, horny, hollow, and more or less transparent part of the stem or scape of a feather.

   • Thus, the four distinct feather parts that have been compared as to amino acid content to note whether or not the composition is uniform are rachis, barbs, calamus and medulla. — 1956
2. •
   A palm in genus Calamus, of rattan palms.
3. •
   Sweet flag (Acorus calamus).
4. •
   A fish of genus Calamus in family Sparidae; certain porgies.
5. •
   A fistular stem without an articulation.
6. •
   (historical) Synonym of fistula (“tube for sucking Eucharist wine”).