Lexical lacunae and non-equivalent units are among the most persistent sources of translation difficulty because they reveal asymmetries in how languages segment experience, conventionalize cultural knowledge, and distribute meaning between lexicon and grammar. When a target language lacks a conventionalized lexical match, translators often compensate through approximation. This compensation can trigger interference, understood here as the uncritical transfer of source-language patterns into the target text, resulting in semantic distortion, pragmatic infelicity, or stylistic incongruity. The present article offers a theoretically grounded and practice-oriented account of how lexical lacunae and non-equivalent units generate interference and how such interference can be prevented. Drawing on translation theory, lacunology, and contrastive semantics, the study develops an integrative mechanism that links detection of lacunarity to controlled choice of translation procedures and to post-translation quality control. The results of the analytical synthesis show that interference is most likely when translators rely on formal similarity, calquing, or dictionary-level equivalence without checking frame compatibility, collocational norms, and communicative function. Preventive mechanisms are effective when they treat lacunarity as a diagnostic signal prompting structured decision-making, documentation of choices, and targeted verification through context, comparable texts, and revision protocols.