Background: A defining characteristic of expertise is the use of intuition to navigate tasks. The construct of intuition and its importance is well-studied in other disciplines, but little is known about how it translates to engineering. Existing literature on intuition does not clearly define the construct and its relationship to problem solving, which creates a substantial gap in our understanding of intuition and its applicability to engineering. Purpose: This study's purpose is to better understand the relationship between expertise, decision-making, and intuition from the perspective of engineering practitioners. We additionally seek to define engineering intuition from this same perspective. Design/Methods: Seventeen semi-structured interviews were conducted with engineering practitioners with at least 6 years of experience. Sensitizing concepts tied to models of expertise development and dual process cognition were used to guide the study's design and data analysis. Iterative qualitative analysis culminating in code mapping supported the development of a definition and theory of engineering intuition. Results: This study's result is an emergent definition of engineering intuition and a complementary framework called Leveraging Intuition Toward Engineering Solutions (LITES). LITES uniquely situates intuition as part of the problem-solving process among experienced engineering practitioners and describes how practitioners use their intuition. Conclusions: This work advances knowledge of the relationship between intuition and expertise in engineering education by providing a definition of engineering intuition and a framework describing intuition's role in engineering problem solving. This contribution furthers efforts to equip current and future engineers with the necessary skills to navigate existing and upcoming societal challenges.