SUMMARY
The lexicons of natural languages are not isomorphic. Reasons for the anisomorphism can be sought on three interrelated planes: language structure, extralinguistic reality, and conceptualisation. Simply put, the relevant differences may reside in the language, the world, the mind, or any combination of these. As a result, what goes under the name of <i>lexicographic equivalence</i> is a rather heterogeneous category. Growing awareness of this fact has resulted over the years in the creation of several tentative typologies of equivalence, one of which is presented below, together with a brief discussion of some strategies for dealing with imperfect equivalence. The remaining part of the article comprises a detailed analysis of a single problem encountered while preparing a new edition of a bilingual dictionary for Polish learners of English. The task at hand involved choosing a viable counterpart for a (Polish) semantic neologism from among a few (English) equivalence candidates. In the discussion, reference is made both to the metalexicographic categories introduced earlier and to such concepts developed by lexical (especially cognitive) semantics which may prove helpful in capturing the meaning differences between the source-language item and its competing target-language renditions. This micro-scale dissection of a single specimen demonstrates that we are still some way from being able to classify, let alone deal with, all the instances of imperfect interlingual correspondence that come our way. Persisting in the efforts to advance our understanding of the complex issues covered by the blanket term <i>lexicographic equivalence</i> thus seems crucial for improving the treatment of meaning in bilingual dictionaries.