Acrostic

Poem in which the first letter of each line is also part of a hidden message. (The same principle can be applied to the last letter of each line, to syllables or words instead of letters and to paragraphs instead of lines.) Acrostics can be a form of poetry, but they are also used as puzzles or as mnemonic devices. Arguably, the best-known acrostic is the mnemonic sentence "My very educated mother just served us nachos"; the initial letters of the words reveal the eight planets of the solar system (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune).