From: rnewtonATkent.edu on a word-a-day mailing list I’m subscribed to:

The most egregious example of gender-bias in English is, I think, the
existence of two words for students. Male students are students; but
female students are co-eds. This originates in schools being for males
only. So, when they allowed girls to come “along” (this is what co-
means), they were viewed as nonessential appendages. Kind of like Adam
being created independently, and then Eve was formed to assist him. I
have insisted that all my students expunge this word from their
vocabulary. I no longer allow them to say they live in a co-ed dorm,
for example, since that implies that the dorms are really there for
the one sex only. There are only male dorms, female dorms, and mixed-
gender dorms (although this is a misnomer, since gender is not the
same as sex; but we can’t very easily call them two-sex dorms without
raising eyebrows; unisex might work?).

E-Mail from wsmith