The word was adopted into English in the nineteenth century from medieval Icelandic treatises on poetics, in particular the Prose Edda of Snorri Sturluson, and derives ultimately from the Old Norse verb kenna “know, recognise; perceive, feel; show; teach; etc.”, as used in the expression kenna við “to name after; to express [one thing] in terms of [another]”, “name after; refer to in terms of”,and kenna til “qualify by, make into a kenning by adding”.