Syntax

Etymology

From Greek syntaxis, "an arranging together," from syn- ("together") + tassein ("to arrange, put in order"). The word was originally military, used for drawing troops up in formation. Applied to language, it keeps that sense of orderly arrangement: syntax is how words are drawn up into working formation.

noun · /SIN-taks/
The set of rules governing how words are arranged into phrases and sentences.
What it names
The structural grammar of a language — the ordering logic that makes "the dog bit the man" mean something different from "the man bit the dog."
Example
Translation software still stumbles over languages whose syntax puts the verb last.
Related idea
Syntax is about the arrangement of words; semantics is about their meaning. A sentence can be perfectly syntactic yet meaningless — "colorless green ideas sleep furiously."