Rising rates of hunger and food insecurity have sparked a major re-evaluation of all aspects of food systems. Because of the multifaceted nature of food insecurity, however, determining what actions should be taken is challenging, especially since reevaluation efforts are led by experts from several disciplines and there is no consensus about which indicators should be used and how they should be measured. Confusion surrounding the meaning of the terms ‘food security’ and ‘food insecurity’ has contributed to this lack of consensus. As indicators inform action, such confusion has slowed those committed to alleviating hunger in identifying the most pressing targets. This review highlights (1) the importance of clearly defining food security and food insecurity and (2) how such definitions affect measures of food insecurity in the United States. While some might say that definitions are an issue of the past or a trivial matter of semantics, we believe that the world’s present rates of hunger and malnutrition are attributable, at least in part, to the lack of consensus on these definitions and their accompanying measurements and indicators. Although the present review can be helpful to academics and policy makers, the primary purpose is to be a resource to those involved in the day-to-day production of food, such as ranchers and farmers by providing an overview of definitions, indicators, and measurements used when discussing food security.