The beginning of the COVID-19 pandemic offers a unique case study for understanding conceptual and linguistic propagation. In early 2020, scientists, politicians, journalists, and other public figures had to, with great urgency, propagate several public health-related concepts and terms to every person they could. This chapter examines the propagation of coronavirus and social distancing and develops a framework for understanding how the language used to express a notion can help or hinder propagation. I argue that anyone designing words, meanings, or concepts for propagation needs to appreciate the three-way causal relationship between language, people’s mental representations, and the extramental world. Using this framework, I explore what makes “social distancing” a bad name for social distancing and why it is unproblematic that “coronavirus” is a scientifically loose way of speaking about the virus. Through this and further study of the many historical examples of linguistic and conceptual propagation, conceptual engineers can better understand the complex challenges facing people who want to propagate words, meanings, or concepts.