To those that are using the term cis in scare quotes, or saying that using the term makes them feel dirty or that they detest the term, here is a quick note.
Cis and Trans are both Latin prefixes. Trans means "across, beyond, or to the opposite side". Cis means "on the same side as".
The prefix trans has applications in words like transfer, transition, transcendence, and therefore became used for transgender or transsexual people, because they go across, beyond, or to the opposite side of, aspects of their body or gender. Like having a gender identity that is on the opposite side of their physical sex, at first, and then transitioning the body. For some people that do not have a clear sex, or have a gender identity that is neither male nor female, they may use the "beyond" meaning of the prefix, like in the word transcendence, to mean that the dichotomy of gender or sex is not relevant to their identity or sex.
Cis as fewer applications, but is used in some places like chemistry. Some people began using the prefix to describe non-trans people, seeing as how it's the opposite Latin prefix. To be cissexual, cisgender, cis-female, or cis, means that one's gender and sex are on the same side as each other.
It's not really a word I use, and didn't use it until page 21 of this thread in response to someone else using it, primarily because a) trans issues rarely come up in conversation anyway, and b) most people won't know the term. But linguistically, there's nothing wrong with the term itself.
So don't worry, it's not going to make you dirty for using the word if you choose to. I promise.
Similarly, the words homo and hetero are prefixes derived from Greek. Homo means "the same", and hetero means "different" or "other". So we can use the prefixes to describe homogeneous or heterogeneous mixtures, and can use the prefixes to describe sexual orientation as homosexual or heterosexual.
Now, I could freak out and say I don't want to be called heterosexual or cissexual, and rather should just be called "normal". Or I can maintain the use of "heterosexual" in quotes but not homosexual, or "cissexual" in quotes but not transsexual, implying one word is more valid than the other. Because, I could argue those homosexual people and cissexual people have to be the ones with the descriptions, not me. But of course I'm not going to do that, because there only reason I can think to do so would be to try to set myself above or better than minorities of sexual orientation or gender identity, when the human condition has multiple variances of things.