Just to be difficult:
www.dictionary.com
Poem:
1. A verbal composition designed to convey experiences, ideas, or emotions in a vivid and imaginative way, characterized by the use of language chosen for its sound and suggestive power and by the use of literary techniques such as meter, metaphor, and rhyme.
2. A composition in verse rather than in prose.
3. A literary composition written with an intensity or beauty of language more characteristic of poetry than of prose.
4. A creation, object, or experience having beauty suggestive of poetry.
Prose:
1. Ordinary speech or writing, without metrical structure.
2. Commonplace expression or quality.
3. Roman Catholic Church. A hymn of irregular meter sung before the Gospel.