coadventure
/kəʊˈædvɛntʃər/Definitions
1. noun
an adventure shared by two or more people, especially a romantic or heroic journey
“The couple embarked on a coadventure through the dense jungle, facing numerous challenges along the way.”
2. noun
a joint undertaking or enterprise, especially a shared activity or project
“The coadventure between the startup and the established company resulted in a revolutionary new product.”