The most lucid (but probably outdated) definition of poem I got is from an old 1974 book by David Swanger called "The Poem as Process." (which I've been reading in bits instead of doing my homework)
He writes: "It is poetry because it is excited, precise, presentational, and evocative; as such it encourages meaning-making by the reader and engages him as co-poet in the act of empathetic re-creation." (p.144)
"But how do we know when a poem achieves precision? ...when it elicits the desired range of responses from the reader. Precision in poetry links the poet to the reader and consists in the effect a word, a line, a stanza, the entire poem, will have." (p. 13)
"...[P]oetry can no more be wholly presentational than it can be wholly discursive. It must be both, but its discursive function must always be supportive of its presentational, never supersede it." (p. 153)
"The poet collaborates with a linguistic culture in the first instance simply by writing in a given language." (p. 164) ---which makes me want to write more Tagalog poems.
Now I feel as if very little of what I've written does justice to that definition.