decussate

The adjective is first attested in 1825, the verb in 1658. Borrowed from Latin decussātus, perfect passive participle of decussō (“to divide crosswise, arrange crosswise or mark with a cross”) (see -ate (adjective-forming suffix) and -ate (verb-forming suffix)), from decussis (“a coin worth ten asses; a cross sign (from the cross shape of the Roman numeral for ten carved on the coins)”), from decem (“ten”) + as (“a Roman coin”).

• IPA^(key): /dɪˈkʌseɪt/

decussate (comparative more decussate, superlative most decussate)

1. Crossed; intersected; resembling a letter X.
3. (zoology) Having anatomical structures or markings crossing each other, typically in an X shape or at right angles.
5. (botany) Having opposite leaves arranged alternately at right angles.
   • 1849, John Craig, “Juniperites”, in A New Universal Etymological, Technological, and Pronouncing Dictionary of the English Language, Embracing All the Terms Used in Art, Science, and Literature, volumes II (Jac–Zyt), London: Published (for the proprietors,) by Henry George Collins, 22 Paternoster Row, →OCLC, page 15:

     Juniperites, ju-ne-per-i′tis, s[ubstantive]. A genus of fossil plants, in which the branches are ranged irregularly; leaves short, obtuse, inserted by a broad base, opposite, decussate, and arranged in four rows.

6. (Can we verify⁽⁺⁾ this sense?) (rhetoric) Consisting of two rising and two falling clauses, placed in alternate opposition to each other.

   a decussated period

• decussant

decussate (third-person singular simple present decussates, present participle decussating, simple past and past participle decussated)

1. To form an X or to cross or intersect.
   • 1949, Herbert Eugene Walter, Leonard Perkins Sayles, Biology of the Vertebrates:

     The two trochlears decussate in the anterior medullary velum.

• decussation
• decussative

decussate

1. feminine plural of decussato

decussāte

1. second-person plural present active imperative of decussō