うやむや・有耶無耶uyamuya[0]heiban (flat)

1. na-adjective, nounindefinite; hazy; vague; unsettled; undecided
   その問題もんだいをうやむやにしておくことはできない。↗

   We shouldn't leave the matter unsettled.

• Synonym曖昧あいまいNeutralThe everyday word for vague or ambiguous, as in 「曖昧な返事」. Use it for general vagueness; 「うやむや」 adds the nuance of something glossed over or left hanging.
• SynonymあやふやNeutralSuggests uncertainty or unreliability, as in 「記憶があやふや」. It stresses that something is shaky and cannot quite be trusted, not that a matter was left unsettled.
• Synonym不明ふめいNeutralObjectively states that something is unknown or unclear, as in 「原因不明」 or 「行方不明」.
• Synonym不明瞭ふめいりょうNeutralUnclear or indistinct, mainly in written style, as in 「発音が不明瞭」. Unlike 「うやむや」, it does not imply deliberately leaving something unsettled.
• Synonym曖昧模糊あいまいもこWrittenA four-character idiom in written style meaning hazy and unclear. Stronger than 「曖昧」 alone; it does not carry the sense of leaving a matter unresolved.
• Synonym不分明ふぶんめいWrittenWritten and rather rare; describes unclear boundaries or facts, as in 「責任の所在が不分明」. No nuance of deliberately dragging things out.
• Synonym模糊もこWrittenA written-style word for dim and hazy, mostly seen in the set phrase 「曖昧模糊」; rarely used on its own.
• Related不確定ふかくていNeutralFairly formal; means not yet fixed or determined, as in 「不確定要素」. It does not imply deliberate vagueness.
• Related未解決みかいけつNeutralObjectively states that a problem remains unsolved. 「うやむや」 instead stresses vagueness and the lack of a firm conclusion.
• Related不定ふていNeutralMeans not fixed or variable, as in 「住所不定」 or 「不定期」; leans toward written style.
• Related不鮮明ふせんめいNeutralRefers to images or impressions lacking sharpness, mainly visual, as in 「画像が不鮮明」.
• Related不確かふたしかNeutralMeans unreliable or uncertain, as in 「不確かな情報」. It stresses trustworthiness — whether something can be counted on.
• RelatedおぼろげNeutralDescribes faint, hazy memories or images, as in 「おぼろげな記憶」. It stresses a dim impression rather than an unsettled matter.
• Related宙ぶらりんちゅうぶらりんNeutralLiterally dangling in mid-air; describes something left hanging, going neither up nor down, as in 「宙ぶらりんの状態」.
• Related未確定みかくていNeutralNot yet confirmed or determined; common in official documents and data, as in 「未確定の情報」.
• Related未決定みけっていNeutralSimply means not yet decided, in a neutral, objective way; it lacks the nuance of something being fudged or glossed over.
• Related不得要領ふとくようりょうNeutralDescribes speech that misses the point or is noncommittal, as in 「不得要領な答え」.
• Antonym明確めいかくNeutralThe antonym: clear and definite, the opposite of hazy 「うやむや」. Note that making something clear does not mean it has been resolved.

For general vagueness, 「曖昧」 is the everyday choice. 「うやむや」 is for matters glossed over or left unsettled: 「うやむやにする」 means to fudge something, as in 「責任をうやむやにする」. 「不明瞭」「曖昧模糊」「不分明」「模糊」 describe unclear states without that nuance; 「あやふや」「不確か」 stress unreliability; 「朧気」「不鮮明」 faint impressions; 「不確定」「未確定」「未決定」「不定」 simply not fixed or decided; 「未解決」「不明」 objective statements; 「宙ぶらりん」 left hanging; 「不得要領」 noncommittal replies; 「明確」 is the antonym — clear, but not necessarily resolved.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 曖昧あいまいではっきりとしていない様子ようす。