A lack of a shared understanding of key terms is acknowledged as a significant barrier to interdisciplinary research. This paper examines the ways in which a broadly interdisciplinary team of academics and youth co-researchers involved in mental health research interpreted a number of research and mental health terms that are central to their work in order to understand conceptual differences in how different stakeholder groups approach these terms. Data was collected in four phases (interviews, written responses, and two participatory ‘living labs’) and was analysed using reflexive thematic analysis. Results revealed a wide disparity in the way participants understood key terms (including: ‘research’, ‘data’, ‘loneliness’, ‘safe space’ and ‘resilience’). Our study highlights the need for more inclusive approaches to mental health research, where diverse perspectives and lived experiences inform both methodology and practice from the outset. In conclusion we suggest a new framework (the EQUITY framework) as a tool to operationalise these findings.