Cosmos
Etymology
Greek "kosmos" meant order and adornment, and Pythagoras is credited with applying it to the orderly universe. The adornment sense survives, oddly, in "cosmetic," while the order sense stands directly against "chaos."
noun · /KOZ-moss/
The universe regarded as an ordered, harmonious whole.
What it names
The universe under the aspect of order — reality as a system, not a heap.
Example
Ancient astronomers assumed a cosmos — a lawful, patterned heaven — long before they could prove the orbits.
Related idea
The ordered counterpart to chaos, and what entropy slowly unwinds; the same root, surprisingly, gives us cosmetics.