In grammar, the comitative case is a grammatical case that denotes accompaniment. Wikipedia

grammatical case denoting company Wikidata

Noun case used to denote companionship. In English, this is usually expressed by the prepositional phrase in company with, together with or with, as in "with the house." Languages that use the comitative case include Estonian, Finnish, Hungarian, Inari Sami, Northern Sami, Skolt Sami, and Quechua. It is also found in many Australian Aboriginal languages, where it is commonly used to form names of places and languages. Wiktionary

Case used to denote companionship. Wiktionary (translation)