Pedagogical bilingual dictionaries are expected to do more than provide translation equivalents: they must support comprehension, accurate production, and the gradual formation of lexical and grammatical competence in learners who operate between two linguistic systems. Traditional bilingual lexicography often treats equivalence as a stable word-to-word relation and represents meaning through short glosses, while contrastive linguistics repeatedly demonstrates that cross-language correspondences are frequently partial, context-dependent, and shaped by differences in semantic segmentation, collocational norms, pragmatic conventions, and culture-specific conceptualization. This article argues that the most productive way to modernize bilingual pedagogical dictionaries is to convert contrastive linguistic results into explicit semantic design principles: a contrastive sense inventory, an “equivalence gradient” (full/partial/functional/zero equivalence), frame-informed meaning explanations, corpus-based collocational templates, and learner-oriented usage warnings that directly target typical interference and errors. The results indicate that contrastive-semantic modeling reduces ambiguity in polysemy alignment, improves learners’ productive choices, and increases the dictionary’s diagnostic value as a tool for preventing negative transfer.