The paper explores the interrelation between the socially biased phenomena, affecting the conceptual domain of “knighthood” in the XIII-XV centuries. Nobility and knighthood as interrelated conceptual entities became increasingly complicated, due to cultural semiosis, which brought about drastic conceptual and semantic changes in the adjectives under scrutiny: worthy, noble, gentle. The analysis of corpus and lexicographic material as well as romances of the period demonstrated that conceptual changes became the major triggers for the large-scale semantic changes within the category.