Expressions about opportunities are used unproblematically in everyday contexts. Yet, the question “What is an opportunity?” has posed a difficult riddle in the academic study of entrepreneurship. Drawing on the philosophy of Ludwig Wittgenstein, we explain that such perplexities are common when words are removed from ordinary language and intellectuals try to grasp what they name. Approaching the opportunity riddle differently, we ask, “How do entrepreneurs use the word ‘opportunity?’” and elucidate an actualization theory of entrepreneurship attuned to the everyday understandings that underlie the meaningful use of the word. Bringing implicit understandings to the foreground contributes to (a) dissolving the mystification over the nature of “opportunity”; (b) clarifying the conceptual foundations of entrepreneurship theory; and (c) reorienting the field toward more conceptually precise ways of thinking about Knightian uncertainty, entrepreneurial success, and the entrepreneurial process. This paper also contributes to the methodology of management studies by demonstrating how attention to the logic of ordinary language can alert us to theoretical dead-ends and enable the development of theory that bridges academic and everyday understandings.