This house's name for the framework of many entities and one shared memory. A named system rather than a general concept.
A modern coinage with no ancient root, and this row says so plainly rather than inventing one. In wide use as a nickname since the mid-20th century (a shortening of Sigmund, Zigmunt, and kin), and fixed in the culture by David Bowie's Ziggy Stardust (1972). The zig- element carries a sense of sharp movement — zigzag, from 18th-century French ziczac.
The house's own front door and dashboard. Named for what it is rather than what it descends from: the quick, familiar, sideways-moving thing that gets you where you are going. Not every word in the Grammar has an ancestor, and the register is honest about which ones do.