collegial

adjective /kəˈliː.dʒi.əl/ formal

Definition

› relating to a friendly relationship between colleagues (= people who work together): The organization has a welcoming collegial atmosphere. › used to describe a method of working in which responsibility is shared between several people: The new chair quickly upset council members, who were used to a more collegial style.

(Definition of collegial adjective from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)