Alex Byrne's article, "Are Women Adult Human Females?", asks a question that Byrne treats as nearly rhetorical. Byrne's answer is, 'clearly, yes'. Moreover, Byrne claims, woman is a biological category that does not admit of any interpretation as (also) a social category. It is important to respond to Byrne's argument, but mostly because it is paradigmatic of a wider phenomenon. The slogan "women are adult human females" is a political slogan championed by anti-trans activists, appearing on billboards, pamphlets, and anti-trans online forums. In this paper, I respond to Byrne's argument, revealing significant problems with its background assumptions, content, and methodology. 1. 1 (Foucault 1972), p. 181. Cited in (Brison 2019). 2 Throughout this paper, I use 'they' as a singular, gender-neutral pronoun. See (Dembroff and Wodak 2018) for a philosophical criticism of gender-specific pronouns. political slogan. Moreover, it is a slogan that has been championed by anti-trans activists, appearing on billboards, pamphlets, and anti-trans online forums. It is 3 important to respond to Byrne's argument, but mostly because Byrne's argument is a paradigmatic instance of a wider phenomenon. So while I directly address Byrne in what follows, many of my arguments apply also to others who make the same or similar arguments. 4 My reconstruction of Byrne's argument is as follows: Premise 1: There is one meaning of 'woman' relevant for philosophical inquiry into the meaning of the term 'woman'. 5 Premise 2: That meaning is the "standard" (or "dominant") meaning. 6 Premise 3: On the "standard" meaning of 'woman', 'woman' refers to the category adult human female. 7 Premise 4: Adult human female is a biological and not social category. 8 Premise 5: Therefore, the single philosophically relevant meaning of the term 'woman' refers to a biological and not social category-namely, adult human female. [1, 2, 3, 4] 3 See also (Corredor 2019) for discussion of far-right political groups' exploitation of anti-trans rhetoric. 4 For this reason, most references to 'Byrne' can be read as shorthand for 'Byrne and those who make similar arguments'. 5 Byrne (2020) frequently refers to "the meaning" of 'woman'. See also p. 19, footnote 29: "If AHF has two interpretations-corresponding to the dominant and resistant meanings of 'woman'-the one clearly at play in the relevant literature is the first." Byrne also refers to resistant meanings as "non-standard" and dominant meanings as "ordinary". 6 See pp. 18-19, footnote 29. It is also worth noting that although Byrne acknowledges that people use gender terms in a variety of ways and that the meanings of these terms are "disputed", they interpret anecdotal data as showing that some people "systematically misapply" gender terms. Byrne does not consider their own uses of gender terms as potential instances of such misapplication. 7 The entirety (or near entirety) of Byrne's section 2 defends Premise 3. While some of the arguments in this section are presented under the guise of epistemological argument...