Grammar

n. [Fr. grammaire, Pr. gramaira, gramairia, for gramadaria, from Lat. as if grammaticaria. See GRAMMARIAN.]

1. The science of language; the theory of human speech; the study of forms of speech, and their relations to one another.
2. The art of speaking or writing with propriety or correctness, according to established usage; the normal or right use of language. “The original bad grammar and bad spelling.” Macaulay.
3. A treatise on the principles of language; a book containing the principles and rules for correctness in speaking or writing.
4. A treatise on the elements or principles of any science.