断言|だんげんdangen[3]nakadaka (mid-high)

1. noun, suru verb, transitive verbassertion; declaration; affirmation
   私は彼かれが潔白けっぱくだと断言だんげんした。↗

   I affirmed that he was innocent.

• Synonym言い切るいいきるNeutralVerb for saying something flatly and finally, as in 「絶対だと言い切る」. Common in speech; 「断言」 leans toward written prose.
• Synonym明言めいげんWrittenWritten noun for stating something explicitly, as in 「明言を避ける」; the point is saying it clearly, leaving no ambiguity.
• Synonym言明げんめいWrittenWritten noun for declaring something clearly; close to 「明言」 and likewise formal in tone.
• Synonym主張しゅちょうNeutralNeutral noun for claiming or advocating a view; the emphasis is on holding one's position, which need not be stated absolutely.
• Synonym確言かくげんWrittenWritten noun for stating something with certainty; rarer than 「断言」 and mostly confined to formal prose.
• Related宣言せんげんWrittenNoun for a formal public declaration, as in 「独立宣言」; the stress is on making something known publicly, not on certainty.
• Related言い張るいいはるNeutralVerb for stubbornly insisting on one's own view, with a hint of unreasonableness that 「断言」 does not carry.
• Related請け合ううけあうNeutralVerb for vouching for something or giving one's assurance; the point is taking responsibility, not merely saying it.
• Related保証ほしょうNeutralNoun for a guarantee or warranty, as in 「品質保証」; it concerns standing behind something, not asserting it.
• Related声明せいめいWrittenWritten noun for an official statement, as in 「共同声明」; more formal and public-facing than 「断言」.
• Related表明ひょうめいWrittenWritten noun for making one's attitude or stance clear, as in 「反対を表明」; about declaring a position, not a fact.
• Related陳述ちんじゅつWrittenWritten noun for giving a statement, as in 「意見陳述」; frequent in legal contexts such as testimony.
• Related公言こうげんWrittenWritten noun for declaring something openly and publicly, as in 「公言してはばからない」.
• Related力説りきせつWrittenWritten noun for arguing a point with force, as in 「重要性を力説」; about stressing, not flat assertion.
• Related言い放ついいはなつNeutralVerb for saying something outright without reserve, often with a cold or arrogant edge, as in 「冷たく言い放つ」.
• Related言い立てるいいたてるNeutralVerb for insisting on something or listing points one by one, often with a nagging, going-on-and-on feel.
• Related道破どうはWrittenRare written noun for stating something decisively; can also mean refuting someone outright with words.
• Related宣するせんするWrittenWritten verb for announcing or proclaiming formally, as in 「開会を宣する」; literary in flavor.
• Antonym保留ほりゅうWrittenWritten noun for holding off or reserving judgment; the direct opposite of asserting something outright.

Use 「断言」 when you state something flatly and without hesitation, as in 「断言できる」; it leans toward written prose. In everyday speech, 「言い切る」 is the natural choice for saying something definitively. Pick 「明言」 for stating something clearly, 「宣言」 for a formal public declaration, 「言い張る」 for stubbornly insisting, and 「表明」 for making a stance known. When you withhold judgment rather than assert, use 「保留」.

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

1. きっぱりと言い切いいきること。