In the present paper, the authors discuss the relationship between the derivatives in French and in Polish, in view of showing their implications for translatology. Beginning with the examination of the factors which determine the character of morphosemantic fields in the two languages, they present the opacity of French and the transparence and the semantic regularity of Polish, illustrating the discussion with the chosen morphosemantic fields. The conclusions based on the analysis thus carried out are undoubtedly important for lexicography and translatology. Since the bilingual dictionaries respect neither the diachronic order, nor the criterion of frequency in the presentation of the meanings of a lexical unit, the authors postulate that the semantic relationship should be reanalyzed in view of the elaboration of a bilingual dictionary which would inform the user about the notional extent at the same time allowing the lexicographer to eliminate the marginal meanings. Besides, there also exists a more economical possibility of accounting for the semantics of the derivatives, by means of formalized references to the particular meanings of the base in the cases where an evident regularity of the semantic relationship can be observed.