Purpose: The purpose of this article is to develop a contextualized definition of the phenomenon of rapidly internationalizing ventures (RIVs) - such as born globals or international new ventures - building upon the commonly noted dimensions of internationalization: speed, degree and scope. Design/methodology/approach: The study builds on a theory informed review of 62 empirical studies on RIVs from the USA and the European Union and an empirical survey among 103 academics in the field of international entrepreneurship. Findings: After specifying the core characteristics of RIVs (speed, degree, and scope of internationalization), it is shown that the discrepancies in definitions result in a dysfunctional fragmentation of empirical results. Thus, research on the phenomenon of RIVs urgently needs contextualized definitions because the three core characteristics are context-sensitive, and will therefore manifest themselves differently across contexts. Research limitations/implications: The paper contributes to international entrepreneurship research by introducing a feasible strategy for defining RIVs which ensures the identification of the very same phenomenon across different contexts, thus bridging the gap between different research contexts and enabling a common body of knowledge to evolve. Practical implications: This insight is particularly important for identifying, analyzing and understanding how managers in RIVs recognize and exploit opportunities in a global sphere and what drives their behaviour and development paths with regard to international activities. Originality/value: Based upon the theoretically-driven identification of the core characteristics of RIVs, the paper formulates the concept of contextualized definitions which enable researchers to identify the phenomenon within any specific context. These relative definitions are suitable for identifying the very same phenomenon in diverse contexts.