Since the publication of Time's cover story "The Transgender Tipping Point," there has been a spate of conservative op-eds in retort. The attacks follow a predictable set of talking points that rely on the reader having no scientific knowledge of the issue. However, when examined from a perspective of peer-reviewed medical consensus and law, these talking points fail utterly.
Trans-Exclusionary Radical Feminism, or TERF, is a loosely-organized collective with a message of hate and exclusion against transgender women in particular. They have attached themselves to radical feminism as a means to attempt to deny trans women basic access to health care, women's groups, restroom facilities, and more.
"Cis" and "cisgender" certainly have a proper place in academia and are likely to be used there for a long time, given how their use has steadily increased. They are also increasingly used in non-LGBT progressive circles as part of policy and sociology discussions. Outside these contexts, however, neither word does us much good.