The "use" of library resources and services is frequently presented in library and information science (LIS) literature as a primitive concept: an idea that need not be defined when it is being measured as an operational variable in empirical research. This project considered representations of library "use" through the Evolutionary Concept Analysis (ECA) method, developed by nursing scholar Beth L. Rodgers to explore the significance of concepts within specific disciplinary, chronological, and theoretical contexts. Analysis of a 200-item sample of the LIS journal literature revealed that "use" is not a monolithic concept but, in fact, has multiple facets of meaning that are deployed in diverse contexts across the LIS publication spectrum. In addition to reviewing key discussions of library "use" in the LIS literature, this article presents a typology of its conceptual facets. (Contains 2 tables and 6 footnotes.)