Grammar is....
1. The study of how words and their component parts combine to form sentences.
2. The study of structural relationships in language or in a language, sometimes including pronunciation, meaning, and linguistic history.
2.
1. The system of inflections, syntax, and word formation of a language.
2. The system of rules implicit in a language, viewed as a mechanism for generating all sentences possible in that language.
3.
1. A normative or prescriptive set of rules setting forth the current standard of usage for pedagogical or reference purposes.
2. Writing or speech judged with regard to such a set of rules.
4. A book containing the morphologic, syntactic, and semantic rules for a specific language.
5.
1. The basic principles of an area of knowledge: the grammar of music.
2. A book dealing with such principles.