 In this section we have focused on semantic accounts of the meaning of ‘woman’, although recently there has also been an explosion of work about the related questions of the metaphysics of gender as a social class, and biological sex as a contested category. Some of these discussions have implications for the meanings of the corresponding terms of ‘woman’ and ‘female’. For example, Saray Ayala and Nadya Vasilyeva (2015) provide an account of biological sex in terms of extended, flexible biological features, where which features count for being male or female can change from context to context, depending on our aims and purposes, and where those extended biological features can be taken to incorporate features of the environment, artificial bodily features, and so on. On the other hand, Helen Daly (2015) has argued that we should favour accounts of ‘female’ and ‘woman’ that do not assume a sharp cut-off point between those who fall under the term and those who do not, since this is morally and politically problematic. In addition, Jennifer McKitrick (2015) has argued that an account of gender in terms of dispositions to behave in certain ways can be politically useful, and can capture the aims of trans women. Finally, Haslanger (2016) has defended a context-sensitive account of ‘sex’, where the term can have different meanings, depending on the aims and purposes of the inquiry in that context.