1650s, from Latin decussatus, past participle of decussare "to divide crosswise, to cross in the form of an 'X,'" from decussis "the figure 'ten'" (in Roman numerals, represented by X) from decem "ten" (see ten). As an adjective, from 1825.
decussate de·cus·sate (dĭ-kŭs'āt', děk'ə-sāt')
v. de·cus·sat·ed, de·cus·sat·ing, de·cus·sates
To cross or become crossed so as to form an X; intersect. adj.
Intersected or crossed in the form of an X.