Poetry is a literary medium "that employs the line as its formal unit, and in which the sound, rhythm and meaning of words are all equally important. Until the modern introduction of the concept of free verse, poetry was characteristically written in regular lines with carefully structured metres, often with rhymes."
"poetry." Philip's Encyclopedia 2008. London: Philip's, 2008. Credo Reference. Web. 11 April 2013.
Poetry is a "form of literature distinguished from prose by the use of metre, rhythm, rhyme, sound (e.g. alliteration and assonance), and figurative language. In general, the requirements of metre and rhyme have demanded a more compressed use of language, involving departures from normal prose syntax."
"poetry." The Macmillan Encyclopedia. Basingstoke: Macmillan Publishers Ltd, 2003. Credo Reference. Web. 11 April 2013.