a three-line unrhymed Japanese poem structurally similar to a haiku but treating human nature usually in an ironic or satiric vein. It is also unlike haiku in that it usually does not have any references to the seasons. Senryū developed from haiku and became especially popular among the common people about the 18th century. It was named for Karai Hachiemon (pen name Senryū), one of the most popular practitioners of the form.