acrostic

Definition 
A poem in which the first letter in each line spells out a word. A well-known example is the notoriously sentimental Mother acrostic. The form's low repute as a literary device is reflected in John Dryden's satiric poem "MacFlecknoe" (1682), in which he advises his hapless adversary to:

Leave writing plays, and choose for thy command

Some peaceful province in Acrostic land.

There thou mayest wings display and altars raise,

And torture one poor word ten thousand ways.