In this paper, we invite the engineering design research community to examine the current state of the engineering design lexicon. We expose the nature and the pervasiveness of practices that often hinder intelligible discourse within the engineering design literature. In particular, we show how such commonly used terms as criterion and metric are used sometimes as synonyms and sometimes not, often leading to material miscommunications. In our view, the engineering design discipline has reached a point in its evolution where clarity and conciseness of its lexicon should be a priority. Today's design activity takes place in a truly multidisciplinary environment, which often involves engineers of diverse backgrounds. Written and oral design discourse among design researchers does not rely on a generally accepted and documented lexicon. These situations are symptomatic of a communication infrastructure that is not effectively facilitating the vigorous evolution of the engineering design discipline of recent years. In addition to detailing the outlines of the design lexicon deficiency, we also propose some avenues to a constructive and productive community-wide discussion on this subject. We invite readers to contribute their views by participating in the web discussion at http://www.eng.buffalo.edu/Research/DBD/.