Variation in how informed consent comprehension tests have been developed may be largely due to the absence of a standardized construct definition. Developing a construct definition would provide a standardized framework for determining how an instrument should be constructed, implemented, interpreted, and applied. Therefore, we utilized the Delphi consensus approach with an international expert panel (N = 19) to gather knowledge, opinions and eventually consensus for a construct definition. Expert consensus was achieved after three revision cycles. While acknowledging that there are limitations to this study, it nonetheless should be considered as a step toward standardization of a construct definition of informed consent comprehension.