Objectives: Clinical practice guidelines (CPGs) are often created through collaboration among organizations. The use of inconsistent terminology may cause poor communication and delays. This study aimed to develop a glossary of terms related to collaboration in guide-line development.Study Design and Setting: A literature review of collaborative guidelines was performed to develop an initial list of terms related to guideline collaboration. The list of terms was presented to the members of the Guideline International Network Guidelines Collaboration Working Group, who provided presumptive definitions for each term and proposed additional terms to be included. The revised list was subsequently reviewed by an international, multidisciplinary panel of expert stakeholders. Recommendations received during this pre-Delphi review were implemented to augment an initial draft glossary. The glossary was then critically evaluated and refined through two rounds of Delphi surveys and a virtual consensus meeting with all panel members as Delphi participants.Results: Forty-nine experts participated in the pre-Delphi survey, and 44 participated in the two-round Delphi process. Consensus was reached for 37 terms and definitions.Conclusion: Uptake and utilization of this guideline collaboration glossary by key organizations and stakeholder groups may facilitate collaboration among guideline-producing organizations by improving communication, minimizing conflicts, and increasing guideline development efficiency.