Definition of decussate in English:

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Pronunciation: /diˈkəsāt/


(Of two or more things) cross or intersect each other to form an X: the fibers decussate in the collar
More example sentences
  • After decussating, these fibers ascend in a compact, ribbon like tract called the medial lemniscus.
  • The central canal and surrounding gray matter appear as though pushed dorsally by the decussating bundles of axons.
  • These decussating bundles can be seen distinctly between the lips of the ventral median fissure.


1Shaped like an X.
1.1 Botany (Of leaves) arranged in opposite pairs, each pair being at right angles to the pair below.
Example sentences
  • This is much simpler than those reproductive organs of living Gnetales with a cone-like inflorescence that is organized by paired or decussate bracts.
  • For example, many pioneer trees exhibit orthotropic (vertically oriented) shoots that successively produce leaves in spiral or decussate phyllotaxy.
  • Orchids, however, have all possible tetrad types: linear, decussate, square, tetrahedral, rhomboid and T-shaped are all reported.



Pronunciation: /ˌdekəˈsāSH(ə)n/
Example sentences
  • The great majority of the pyramidal fibers which arise in the cerebral cortex and descend through the pyramids of the medulla cross in the decussation, most of the remainder forming the uncrossed ventral corticospinal tract.
  • The brainstem has been cut through the inferior colliculi and the decussation of the superior cerebellar peduncles.
  • The pyramids rapidly diminish in size at the level of the decussation, reflecting the fact that the great majority of corticospinal fibers leave the pyramids at the decussation.


Mid 17th century (as a verb): from Latin decussatus, past participle of decussare 'divide crosswise', from decussis (describing the figure X, i.e., the Roman numeral for the number 10), from decem 'ten'.

For editors and proofreaders

Syllabification: dec·us·sate

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