CT is an acronym for Cubicle Trash; i.e., the people you work with who are not worthy of their own office. Traditionally, this is a slovenly group with limited intellectual capacity and a propensity for constant confusion, however they're smarter than retards and can hold down a job. Oddly enough, most CTs have a penchant for party planning and costume masquerades.
Hey, should we invite Nancy to our smoke break? Are you fucking kidding me? I wouldn't be caught dead with that stanky CT.