Wikipedia
Effemimania (from effeminacy) is a term coined by American transsexual writer and biologist Julia Serano to describe what she calls a cultural obsession with male femininity. Serano describes effemimania as "first and foremost an expression of traditional sexism," and uses as an example of it researchers who believe femininity is inferior to masculinity, and who therefore pathologize boys and men who appear to them to be inexplicably relinquishing the latter in favour of the former.
Serano believes feminine men and boys are more culturally threatening than masculine women and girls. In her book Whipping Girl: A Transsexual Woman on Sexism and the Scapegoating of Femininity, Serano writes that the lion's share of research into children with non- normative gender expression has targeted femininity in boys rather than masculinity in girls and tends to conflate feminine gender expression, male homosexuality and male-to-female transsexuality, treating all three as though they were symptoms of the same "disease." Serano says it's wrong to view effemimania as simply a manifestation of homophobia or transphobia, because it is femininity specifically that is being targeted and devalued, with researchers pathologizing feminine men more than they do masculine women, claiming trans men are more psychologically stable than trans women, and overly sexualizing trans women. Similar concepts are sissyphobia and femmephobia.
Effemimania is also the title of a song by the Maryland punk band War on Women.