Iambus or iambic poetry was a genre of ancient Greek poetry that included but was not restricted to the iambic meter and whose origins modern scholars have traced to the cults of Demeter and Dionysus. The genre featured insulting and obscene language and sometimes it is referred to as "blame poetry". For Alexandrian editors, however, iambus signified any poetry of an informal kind that was intended to entertain, and it seems to have been performed on similar occasions as elegy even though lacking elegy's decorum. The Archaic Greek poets Archilochus, Semonides and Hipponax were among the most famous of its early exponents. The Alexandrian poet Callimachus composed "iambic" poems against contemporary scholars, which were collected in an edition of about a thousand lines, of which fragments of thirteen poems survive. He in turn influenced Roman poets such as Catullus, who composed satirical epigrams that popularized Hipponax's choliamb.Horace's Epodes on the other hand were mainly imitations of Archilochus and, as with the Greek poet, his invectives took the forms both of private revenge and denunciation of social offenders.
Originally "iambos" (ἴαμβος) denoted a type of poetry, specifically its content, and only secondarily did it have any significance as a metrical term. This emerges for example from the fact that Archilochus, a famous iambic poet, was once criticized for being "too iambic" The genre appears to have originated in the cult of Demeter, whose festivals commonly featured insulting and abusive language (αἰσχρολογία, aischrologia). A figure called "Iambe" is even mentioned in the Homeric Hymn to Demeter, employing language so abusive that the goddess forgets her sorrows and laughs instead. The abuse of a divinity however is quite common in other cults too, as an ironic means of affirming piety: "Normality is reinforced by experiencing its opposite".