The Collaborative International Dictionary
Universal grammar \U`ni*ver"sal gram"mar\, n.
(Linguistics) the principles forming the basis for the human ability to understand language.
(Linguistics) the general properties and constraints common to all human languages; also, the study of such principles.
Wiktionary
n. (context linguistics English) A hypothetical innate abstract system in the human brain that underlies the grammar of all human languages.
Wikipedia
Universal grammar (UG) is a theory in linguistics, usually credited to Noam Chomsky, proposing that the ability to learn grammar is hard-wired into the brain. It is sometimes known as "mental grammar", and stands opposed to other "grammars", e.g. prescriptive, descriptive and pedagogical. The theory suggests that linguistic ability becomes manifest without being taught (see the poverty of the stimulus argument), and that there are properties that all natural human languages share. It is a matter of observation and experimentation to determine precisely what abilities are innate and what properties are shared by all languages.
Usage examples of "universal grammar".
If we could simply stack all these 'faces' one on top of another to work out the rules of universal grammar that waywell, we'd have a map of the whole possible territory of human thoughteverything we can ever hope to express, as a species.
The orphan's language analysis networks had begun fine-tuning the universal grammar they encoded, rapidly homing in on the conventions of linear.