Chinese puzzle, argument, baffling problem, brain twister, conundrum, crossword puzzle, crux, enigma, enigmatic question, excuse, explanation, floorer, for which, for why
, from what cause, ground, how come, jigsaw puzzle, knot, knotty point, mind-boggler, mystery, mystification, nut to crack, on what account, perplexed question, perplexity, poser, pourquoi, pretense, pretext, problem, proof, puzzle, puzzlement, puzzler, question, question mark, rational ground, rationale, reason, reason for, reason why
, riddle, sixty-four dollar question, stated cause, sticker, stumper, the big idea, the idea, the whatfor, the wherefore, the why
, tough proposition, underlying reason, vexed question, what for, wherefore, whyever, whyfor
affirmance, affirmation, statement, allegation, assertion, predication, declaration, word, averment, confirmation, asseveration, adjuration, swearing, oath, affidavit, deposition, avouchment, assurance, protest, protestation, profession, acknowledgment, legal pledge, pronouncement, solemn averment, solemn avowal, solemn declaration, remark, observation, position, saying, dictum, sentence, ipse dixit, emphasis, weight, dogmatism, dogmatics, asserting, declaratory, predicatory, pronunciative, affirmative, soi-disant, positive, certain, express, explicit, absolute, emphatic, flat, broad, round, pointed, marked, distinct, decided, confident, trenchant, dogmatic, definitive, formal, solemn, categorical, peremptory, unretracted, predicable, affirmatively, in the affirmative, with emphasis, ex-cathedra, without fear of contradiction, as God is my witness, I must say, indeed, i' faith, let me tell you, why
, give me leave to say, marry, you may be sure, I'd have you to know, upon my word, upon my honor, by my troth, egad, I assure you, by jingo, by Jove, by George, troth, seriously, sadly, in sadness, in sober sadness, in truth, in earnest, of a truth, truly, perdy, in all conscience, upon oath, be assured, yes, I'll warrant, I'll warrant you, I'll engage, I'll answer for it, I'll be bound, I'll venture to say, I'll take my oath, in fact, forsooth, joking apart, so help me God, not to mince the matter, quoth he, dixi.