A difficult problem.

synonyms: brain-teaser, enigma, riddle.

Roget 520: equivocalness etc. adj.; double meaning etc. 516; ambiguity, double entente, double entendre [Fr.], pun, paragram^†, calembour^†, quibble, equivoque [Fr.], anagram; conundrum etc. (riddle) 533; play on words, word play etc. (wit) 842; homonym, homonymy [Gramm.]; amphiboly^†, amphibology^†; ambilogy^†, ambiloquy^†.    Sphinx, Delphic oracle.    equivocation etc. (duplicity) 544; white lie, mental reservation etc. (concealment) 528; paltering.    ... show more

Roget 533: secret; dead secret, profound secret; arcanum^†, mystery; latency etc. 526; Asian mystery^†; sealed book, secrets of the prison house; le desous des cartes [Fr.].    enigma, riddle, puzzle, nut to crack, conundrum, charade, rebus, logogriph^†; monogram, anagram; Sphinx; crux criticorum [Lat.].    maze, labyrinth, Hyrcynian wood; intricacy, meander.    problem etc. (question) 461; paradox etc. (difficulty) 704; unintelligibility etc. 519; terra incognita etc. (ignorance) 491.    ... show more

Roget 842: wit, humor, wittiness; sense of humor; attic wit, attic salt; atticism^†; salt, esprit, point, fancy, whim, drollery, pleasantry.    farce, buffoonery, fooling, tomfoolery; shenanigan [U.S.], harlequinade etc. 599^†; broad farce, broad humor; fun, espieglerie [Fr.]; vis comica [Lat.].    jocularity; jocosity, jocoseness^†; facetiousness; waggery, waggishness; whimsicality; comicality etc. 853.    banter, badinage, retort, repartee, smartness, ready wit, quid-pro-quo; ridicule etc. 856.    jest, joke, jape, jibe; facetiae [Lat.], levity, quips and cranks; capital joke; canorae nugae [Lat.]; standing jest, standing joke, private joke, conceit, quip, quirk, crank, quiddity, concetto^†, plaisanterie [Fr.], brilliant idea; merry thought, bright thought, happy thought; sally; flash of wit, flash of merriment; scintillation; mot [Fr.], mot pour rire [Fr.]; witticism, smart saying, bon-mot, jeu d'esprit [Fr.], epigram; jest book; dry joke, quodlibet, cream of the jest.    word-play, jeu de mots [Fr.]; play of words, play upon words; pun, punning; double entente, double entendre [Fr.] etc. (ambiguity) 520; quibble, verbal quibble; conundrum etc. (riddle) 533; anagram, acrostic, double acrostic, trifling, idle conceit, turlupinade^†.    old joke, tired joke, flat joke, Joe Miller^†.    ... show more

Dutch: woordraadsel, hersenbreker, raadselachtige zaak, enigma, raadsel
Polish: enigmat