An N-ary Relation is a finitary relation with more than two relation arguments.
- (Noy & Rector, 2006) ⇒ Natasha Noy and Alan Rector. (2006). “Defining N-ary Relations on the Semantic Web." W3C Working Group Note 12 April 2006 (W3C).
- … in some cases, the natural and convenient way to represent certain concepts is to use relations to link an individual to more than just one individual or value. These relations are called n-ary relations. For example, we may want to represent properties of a relation, such as our certainty about it, severity or strength of a relation, relevance of a relation, and so on. Another example is representing relations among multiple individuals, such as a buyer, a seller, and an object that was bought when describing a purchase of a book. This document presents ontology patterns for representing n-ary relations in RDF and OWL and discusses what users must consider when choosing these patterns.