自明|じめいjimei[0]heiban (flat)

1. na-adjective, no-adjectiveself-evident; obvious; axiomatic; self-explanatory; trivial
   ジョーダンがこの実験じっけんでメイン・エンジンを交換こうかんしたことは自明じめいである。↗

   That Jordan replaced the main engine in this experiment is self-evident.

• Synonym明瞭めいりょうNeutralRefers to being clear and easy to understand, as in 「発音が明瞭」; it stresses clarity of expression, while 「自明」 stresses needing no proof.
• Synonym明らかあきらかNeutralA native-Japanese word for something obvious or clear, as in 「明らかな間違い」; much wider in use than 「自明」.
• Synonym当然とうぜんNeutralMeans natural or to be expected, common in both speech and writing; it stresses what is proper or deserved, not what needs no proof.
• Synonym一目瞭然いちもくりょうぜんNeutralA four-character idiom for something you understand at a single glance; it stresses being evident to the eye.
• Synonym言わずもがないわずもがなNeutralA set phrase centered on 'it goes without saying', though it can also mean something better left unsaid.
• Related明確めいかくNeutralMeans clear-cut and precise, as in 「明確な基準」; it stresses that boundaries are clearly drawn.
• Related明晰めいせきNeutralDescribes sharp, clear thinking, as in 「頭脳明晰」; it stresses clarity of the mind or intellect.
• Related明快めいかいNeutralMeans clear-cut and crisp, as in 「明快な説明」; it stresses that something is stated cleanly and decisively.
• Related決まりきったきまりきったNeutralMeans fixed and unvarying, the same old pattern; it stresses monotony and predictability, not self-evidence.
• RelatedさやかWrittenAn elegant, old-fashioned word for clear and bright, said mainly of moonlight or sound; literary rather than everyday.
• RelatedクリアNeutralA loanword for clear or transparent, also used for clearing a hurdle or completing a stage; it lacks the 'needs no proof' nuance of 「自明」.
• Related見え見えみえみえCasualColloquial and often sarcastic: an intention or trick that is seen through at a glance.
• Antonym不明ふめいNeutralAntonym: unclear, unknown, or unidentified — the opposite of something so evident it needs no proof.
• Antonym曖昧あいまいNeutralAntonym: vague and ambiguous, without clear definition; the direct opposite of 「自明」.

Use 「自明」 for something evident in itself that needs no proof; it leans toward written, formal prose, as in 「自明の理」 and 「自明のこと」. For plain 'obvious', say 「明らか」; for something clear at a glance, 「一目瞭然」; for what naturally should be so, 「当然」. The main antonym is 「曖昧」.

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

1. 証明しょうめいせずともそれ自体じたいが明白めいはくであること。また、そのさま。