desireearmfeldt is doing a better job defining the difference descriptively rather than proscriptively; I think of blouses as gender-standard for women only, and shirts as gender-standard for both men and women, in a way that skirts are gender-standard for women only and pants are (now) gender-standard for both men and women. (And kilts are unusual but non-gendered; the difference between kilts and skirts is another interesting line to draw...)