An acrostic poem is a type of poem that uses a word as a subject with each line starting with a letter of the word. For instance, the word "cat" could be used as a subject for an acrostic poem. The poem could be something like cool as a cucumber, agile as could be and tiny whiskers.
Acrostic poems are arranged vertically, and the lines of the poem do not have to rhyme. The lines used should have something to do with the subject word to be a true acrostic poem. For instance, if someone was to write an acrostic poem with a person's name as the subject, they should use lines that make them think of the person. A great way to think of lines is to brainstorm ideas and use a thesaurus to find synonyms of the words that start with the letter needed.