rachis

 
Pronunciation: /ˈreɪkɪs/
(also rhachis)

noun (plural rachides /-kɪdiːz/)

  • 1 Botany a stem of a plant, especially a grass, bearing flower stalks at short intervals.
  • the midrib of a compound leaf or frond.
  • 2 Anatomy the vertebral column or the cord from which it develops.
  • 3 Ornithology the shaft of a feather, especially the part bearing the barbs.

Origin:

late 18th century: modern Latin, from Greek rhakhis 'spine'. The English plural -ides is by false analogy