decussate
To form an X or to cross or intersect.
The two trochlears decussate in the anterior medullary velum.
Where it comes from
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”).
Adapted from the Wiktionary entry decussate (CC BY-SA 4.0).