‘Gender’ denotes both the conceptual category referring to things or persons that have essential properties in common and that differ in inessential properties (analogously to kind, species, class, type, from the Latin genus), and the grammatical category distinguishing between masculine and feminine (in some languages from neuter too). In the first meaning ‘gender’ refers to human kind; in the second to male/female distinction. At a linguistic and semantic level the structural ambiguity of the term is evident, as it can be used both to indicate the individuals belonging to the human species (insofar as possessing common features, that is having reason, differently from other animal and vegetable species), including males and females, and to indicate the male/female distinction. Just to complicate the matter, there is the added fact that in the sphere of feminist and feminine thought ‘gender’ is often used to indicate women, privileging the peculiarity of the female condition in the use of the term, considered historically, socially and culturally disadvantaged with respect to the male one and therefore in need of special consideration. The use of the word in reference to some disciplines has become widespread (for example, gender politics, gender rights, gender economics, gender sociology, gender medicine, gender pharmacology, etc.) to denote the need for a specific consideration of women in the different sectors of knowledge and practice.