The Concept of "Pedagogical Dictionary" in Contemporary Lexicographic Theory:Definitions, Boundaries, and Taxonomies

The term 'pedagogical dictionary' is pervasive in the metalexicographic literature yet conspicuously under-defined: scholars and practitioners use it to denote a heterogeneous range of reference works whose shared properties remain contested. This paper undertakes a systematic conceptual analysis of the term 'pedagogical dictionary' as it has been used in English-language lexicographic theory from 1942 to the present, with the aim of establishing principled definitional criteria, mapping the conceptual boundaries of the category, and proposing a multi-dimensional taxonomy for its internal classification. Through a critical review of 45 foundational metalexicographic sources and a comparative terminological analysis across five scholarly traditions (British, American, European continental, Scandinavian, and Central Asian), we identify four defining criteria that together constitute a necessary and sufficient definition of the pedagogical dictionary as a lexicographic genre: (1) non-native user orientation, (2) pedagogically controlled metalanguage, (3) SLA-informed microstructural design, and (4) instructional or self-study deployment context. We further propose a four-dimensional taxonomy structured around language mode, user profile, medium, and lexical scope, and examine three contested boundary cases — the bilingualised dictionary, the subject-specific learner dictionary, and the AI-augmented digital dictionary — where the limits of the category are currently under negotiation. The proposed definitional and taxonomic framework offers a conceptual foundation for comparative metalexicographic research and provides practical criteria for dictionary evaluation, design, and pedagogy.