An acrostic poem is one where the first word of every line spells something. Like this:

11/28/13
this is just to say: i stuffed a lot of butter
underneath that turkey’s skin, and I’m
really hoping it’s a delicious dish. the
kids will probably just eat mac ‘n’ cheese.
even though that turkey’s the butteriest.
you know that’s right.

And that, friends, is the last poem I’ll be writing for the foreseeable future.