The aim of the article is to contribute to the growing body of research on kennings, a figure of speech frequently used in Old Norse poetry. The paper addresses three research questions: How does the decoding process of kennings work? Is there a basic textual structure that supports this interpretation process? Is the structure of kennings in the oldest poems more fixed and regulated than the research literature suggests? The article discusses possible interaction patterns between metaphor and metonymy, and it is argued that the structure of kennings is in line with the formula "metaphor from metonymy" suggested by Goossens' (1990, 1995a). It is observed that this is also true of Anglo-Saxon riddles whose character as interaction phenomenon between metaphor and metonymy was observed by Stewart (1979). A cognitive matrix is suggested which illustrates the unique character of the kenning system compared to other creative metaphors.