Definition of prepyramidal in US English:

prepyramidal

adjective

Anatomy
  • Of or relating to the pyramids of the medulla oblongata.

Origin

Mid 19th century; earliest use found in Richard Owen (1804–1892), comparative anatomist and palaeontologist. From pre- + pyramidal.

Pronunciation

prepyramidal

/ˌpriːpɪˈramɪdl/