This is the kind of topic that makes me wish we could respond directly to other people's comments under their comments, in threaded style. It'd make it easier to keep track of who is discussing what with whom, for one thing.
For anyone who's read this far down and not figured out what "cis" means, here's a definition from the Urban Dictionary:
"Short for 'cisgender' (opposite of 'transgender'), used to describe someone whose gender identity matches their anatomical gender at birth."
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http://www.urbandictionary.com/define.ph…
It has a good entry for "cisgendered," too:
The opposite of transgendered, someone who is cisgendered has a gender identity that agrees with their societally recognized sex.
Many transgender people prefer "cisgender" to "biological", "genetic", or "real" male or female because of the implications of those words. Using the term "biological female" or "genetic female" to describe cisgendered individuals excludes transgendered men, who also fit that description. To call a cisgendered woman a "real woman" is exclusive of transwomen, who are considered within their communities to be "real" women, also.
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http://www.urbandictionary.com/define.ph…