1.  acrostic(n = noun.communication) word square - a puzzle where you fill a square grid with words reading the same down as across;
is a kind of mystifier, puzzle, puzzler, teaser

2.  acrostic(n = noun.communication) - verse in which certain letters such as the first in each line form a word or message;
is a kind of literary composition, literary work

1.  A composition, usually in verse, in which the first or the last letters of the lines, or certain other letters, taken in order, form a name, word, phrase, or motto. [1913 Webster]

2.  A Hebrew poem in which the lines or stanzas begin with the letters of the alphabet in regular order (as Psalm cxix.). See Abecedarian. [1913 Webster]

   Pertaining to, or characterized by, acrostics. [1913 Webster]

acrostic, n.
1 a poem or other composition in which certain letters in each line form a word or words.
2 a word-puzzle constructed in this way.

Idiom:
double acrostic one using the first and last letters of each line. single acrostic one using the first letter only. triple acrostic one using the first, middle, and last letters.

Etymology:
F acrostiche or Gk akrostikhis f. akron end + stikhos row, line of verse, assim. to -IC

N  wit, humor, wittiness, sense of humor, attic wit, attic salt, atticism, salt, esprit, point, fancy, whim, drollery, pleasantry, farce, buffoonery, fooling, tomfoolery, shenanigan, harlequinade, broad farce, broad humor, fun, espieglerie, vis comica, jocularity, jocosity, jocoseness, facetiousness, waggery, waggishness, whimsicality, comicality, banter, badinage, retort, repartee, smartness, ready wit, quid- pro-quo, ridicule, jest, joke, jape, jibe, facetiae, levity, quips and cranks, capital joke, canorae nugae, standing jest, standing joke, private joke, conceit, quip, quirk, crank, quiddity, concetto, plaisanterie, brilliant idea, merry thought, bright thought, happy thought, sally, flash of wit, flash of merriment, scintillation, mot, mot pour rire, witticism, smart saying, bon-mot, jeu d'esprit, epigram, jest book, dry joke, quodlibet, cream of the jest, word-play, jeu de mots, play of words, play upon words, pun, punning, double entente, double entendre, quibble, verbal quibble, conundrum, anagram, acrostic, double acrostic, trifling, idle conceit, turlupinade, old joke, tired joke, flat joke, Joe Miller, witty, attic, quick-witted, nimble-witted, smart, jocular, jocose, humorous, facetious, waggish, whimsical, kidding, joking, puckish, playful, merry and wise, pleasant, sprightly, light, spirituel, sparkling, epigrammatic, full of point, ben trovato, comic, zany, madcap, funny, amusing, jokingly, in joke, in jest, in sport, in play, adhibenda est in jocando moderatio, gentle dullness ever loves a joke, leave this keen encounter of our wits, just joking, just kidding, surely you jest!.