There are various contexts and implications for the question „What is poetry?” Genre-theory is only one of them, the self-reflection of poets and the border-policing attempts of literary establishments being the others. In a genre-theoretical attempt at a definition, it is advisable to aspire to terminological precision, although it would put a distance between the argument and everyday usage. Throughout its history the term ‘poetry’ has been used in the following senses: verbal art in general, fiction, all works in verse and lyric. Today, the last mentioned sense seems to prevail. We argue that conceptual consistency is occluded by the traditional triad of epic, dramatic and lyric, if taken as universal and necessary natural kinds of literature, and by the opposition of prose to poetry rather than verse. There is no single basis for distinguishing the three kinds, the triad is a relatively recent product of the history of poetics, and the opposition of poetry to prose looks like a category mistake. Our attempt at a definition results in a formal and external minimal formulation: poem is a short text in verse. Verse in turn is defined by the possibility of enjambment, the most evident signal of which is graphical layout. The next part of the essay attempts to furnish this minimal formal definition with a bunch of prototypical features.