This paper is the first of a two-part series. It presents a research study that aimed to provide a more contextual description of the commonly applied definition of interprofessional education (IPE) offered in 2002 by the Centre for the Advancement of Interprofessional Education (CAIPE) in the UK: "when two or more professions learn with, from and about each other to improve collaboration and quality of care." The study confirmed and consolidated key characteristics of IPE by exploring the meaning of with, from and about. The words with, from and about were regarded as complex. Words describing learning with each other included active engagement, co-location and equally valued. Concepts linked to learning about included knowing about people outside their professional role and interaction. Learning from others was characterized by trust, respect and confidence in others' knowledge. Although learning about others was described as the first part of learning with, from and about, there were mixed views on whether learning with or from formed the second part of the definition. Based on this work, the second paper in this series presents a proposed taxonomy for IPE that may serve to inform emerging applications for IPE in the context of education, service delivery and policy. This research contributes to an emerging understanding of IPE that will support competency development and sound curriculum design, continuing professional development and evaluation of the impact of IPE and collaboration on health outcomes.