Definition of octarch in US English:

octarch

adjective

Botany
  • Relating to, characterized by, or designating a vascular bundle having eight strands of xylem arising from eight distinct points of origin.

Origin

Late 19th century; earliest use found in Frederic Bower (1855–1948), botanist. From octo- + -arch, after German octarch.

Pronunciation

octarch

/ˈɒktɑːk/