[electronvolt]

I'd disagree as far as your position on the word "gender"--I think actually "race" is a much better example of something that has had many meanings over the course of its lifetime in the language, and isn't necessarily well defined even now.

Gender as a term that relates to people, and not words (as in the sense of the gender of a noun in Latin-family languages), has been pretty well defined since it was introduced in the 1950s--specifically as a way to differentiate between biological sex (male, female, intersex, etc.) and the social roles that people play that may or may not actually be related to biological sex (men/women/boy/girl/etc.). It's always been quite well defined, although some people feel that it either doesn't make sense to differentiate between biological sex and gender (e.x. because, perhaps, they believe that social gender roles are innate conditions of biological sex).

[oldandtired]

Just a point, The word "gender" was brought into the English language somewhere in the 14th century, so we are looking at 600 - 700 years of usage and has it roots in propagation and breeding.

Your disagreement over the meaning of the word "gender" just highlights the accuracy of my "position".