From the perspective of writing concepts are most readily identified through conceptual words deployed by writers to evoke conceptual meanings in readers. Although every word has some conceptual weight, this article focuses on words associated with core ideas or classifications or connections of domains of thought--the kinds of terms attended to in the history of ideas that are at the forefront of discussions in disciplines and that undergraduates grapple with. Such concepts are fluid within historically evolving and socially varying situations, and specific conceptual terms circulate within specific epistemic communities as part of specific intellectual practices, associated with specific genres. These domain-specific conceptual terms create challenges of internalization for novices, and become the basis for thought gists of those enculturated into disciplinary ways of thought. In each new communicative situation calling for new statements, however, internal gists must be externalized to create publically shareable articulations of thoughts, undergoing the disciplines gaining the understanding and engagement of readers within the epistemic activity system.