ENThe author investigates the Old Prussian translation of Luther’s Smaller Cathechism by means of a comparative and contrastive analysis of the Old Lithuanian and Old Latvian Translations of the same text. By relying on philological, linguistic and theological arguments, two case-studies (Germ. leyder, and the OPr. expression ∫en brendekermnen po∫tā∫ei «Schwanger wir∫t») are presented in detail. Special attention is paid to the historical semantics of the investigated terms.