Synchysis is an interlocked word order, in the form A-B-A-B; which often display change and difference. This poetry form was a favorite with Latin poets. They are often employed to demonstrate such change within the event in which they are situated; on occasion, there are synchyses within a poem which were not intended but happened to be written in such a way.
A synchysis may be opposed to chiasmus, which is in the form A-B-B-A.
A line of Latin verse in the form adjective A - adjective B - verb - noun A - noun B, with the verb in the center (or a corresponding chiastic line, again with the verb in the center), is known as a golden line. An example of this is aurea purpuream subnectit fibula vestem, "a golden clasp bound her purple cloak" (Virgil, Aeneid 4.139): the line translates word-by-word as "golden purple bound clasp cloak" (endings on the Latin words indicate their syntactical relationship, where in English word order would do the same job).