Disagreement exists within the UK and Ireland regarding how Longitudinal Integrated Clerkships should be defined, and the relevance of international definitions. In this modified, online Delphi study, we presented the UK and Ireland experts in Longitudinal Integrated Clerkships with statements drawn from international definitions, published LIC literature, and the research team's experience in this area and asked them to rate their level of agreement with these statements for inclusion in a bi-national consensus definition. We undertook three rounds of the study to try and elicit consensus, making adaptations to statement wording following rounds 1 and 2 to capture participants' qualitative free text-comments, following the third and final round, nine statements were accepted by our panel, and constitute our proposed definition of Longitudinal Integrated Clerkships within the UK and Ireland. This definitional statement corresponds with some international literature but offers important distinctions, which account for the unique context of healthcare (particularly primary care) within the UK and Ireland (for example, the lack of time-based criteria within the definition). This definition should allow UK and Irish researchers to communicate more clearly with one another regarding the benefits of LICs and longitudinal learning and offers cross-national collaborative opportunities in LIC design, delivery and evaluation.