Towards a theory of definition

A brief theoretical statement on definition is advanced, followed by a study of the development of definition in children aged 5;0-10;0. The empirical findings suggest that the emergence of superordinate terms in definition cannot be adequately accounted for simply by appeal to changes in underlying knowledge, or to selectional restrictions on the structure of the definiens. Rather, the development of definition can best be characterized as the gradual articulation of a conventional definitional form out of the more general forms of ordinary oral discourse. It is suggested that definitions are expressions of word meaning that reflect the unique requirements of a literate register, and that the increasing dominance of superordinate terms in definitions reflects in part the adoption of this conventional form of expression.