The goal of this contribution is to shed light on Italian nouns ending in -essa, focusing on the ones referring to female animals and women (such as 'elefantessa' and 'duchessa'). Firstly, we describe the semantic and formal properties of these nouns. In the second part of the contribution we investigate when, how and why the negative values typically associated with nouns ending in -essa arose, highlighting the formal, semantic and pragmatic parameters that trigger these values. Our investigation is based both on metalinguistic comments, which make it possible to reconstruct the perception of essa-ending nouns throughout the history of Italian, and on a qualitative analysis of the ways in which 19th century journals and magazines use the occupational term professoressa.