Model-based Systems Engineering (MBSE) has emerged as a decisive approach in complex systems design. Within the MBSE landscape, terminologies such as “approach”, “methodology”, “method”, “process”, and other related definitions, along with synonymous terms, play crucial roles in shaping practices, guiding research, and fostering clarity in communication. However, the interpretation and application of these terms can vary across the literature, which may lead to confusion and inconsistency in their usage. This paper proposes a unified set of MBSE definitions to establish clearer distinctions and improve understanding. To validate the proposed definitions, this paper analyzes recently published journal articles, examining how accurately these terms are applied in real-world studies. By comparing the theoretical definitions with the terminology used in practice, the current paper highlights areas of misapplication and suggests ways to improve clarity and consistency in future research. The goal is to contribute to a more precise and consistent use of terminology within the MBSE community, thereby fostering better communication and a more effective application of these concepts.