| 1. | the study of the way the sentences of a language are constructed; morphology and syntax. |
| 2. | these features or constructions themselves: English grammar. |
| 3. | an account of these features; a set of rules accounting for these constructions: a grammar of English. |
| 4. | Generative Grammar. a device, as a body of rules, whose output is all of the sentences that are permissible in a given language, while excluding all those that are not permissible. |
| 5. | prescriptive grammar. |
| 6. | knowledge or usage of the preferred or prescribed forms in speaking or writing: She said his grammar was terrible. |
| 7. | the elements of any science, art, or subject. |
| 8. | a book treating such elements. |
(téchnē) grammatical (art); see -ar 2 
The rules for standard use of words. A grammar is also a system for classifying and analyzing the elements of language.
grammar
A formal definition of the syntactic structure of a language (see syntax), normally given in terms of production rules which specify the order of constituents and their sub-constituents in a sentence (a well-formed string in the language). Each rule has a left-hand side symbol naming a syntactic category (e.g. "noun-phrase" for a natural language grammar) and a right-hand side which is a sequence of zero or more symbols. Each symbol may be either a terminal symbol or a non-terminal symbol. A terminal symbol corresponds to one "lexeme" - a part of the sentence with no internal syntactic structure (e.g. an identifier or an operator in a computer language). A non-terminal symbol is the left-hand side of some rule.
One rule is normally designated as the top-level rule which gives the structure for a whole sentence.
A grammar can be used either to parse a sentence (see parser) or to generate one. Parsing assigns a terminal syntactic category to each input token and a non-terminal category to each appropriate group of tokens, up to the level of the whole sentence. Parsing is usually preceded by lexical analysis. Generation starts from the top-level rule and chooses one alternative production wherever there is a choice.
See also BNF, yacc, attribute grammar, grammar analysis.