失神・失心|しっしんshisshin[0]heiban (flat)

Common
Which spelling to use
失神失神 is the most common written form and the recommended default for learners. It is written entirely in kanji.
失心失心 is a rarely used written variant, so learners will seldom need to choose it. Recognize it as an alternative form of the same word.
Definitions
  1. noun, suru verb, intransitive verbfainting; losing consciousness; passing out
    彼女かのじょは失神しっしんしそうに見みえました。↗
    It seemed as if she was going to faint.
  2. noun, medicinesyncope
Conjugation
Dictionary form失神する(しっしんする)
Polite (masu)失神します(しっしんします)
Negative (nai)失神しない(しっしんしない)
polite (masen)失神しません(しっしんしません)
classical zu / nu失神せず・失神せぬ(しっしんせず・しっしんせぬ)
Past (ta)失神した(しっしんした)
polite (mashita)失神しました(しっしんしました)
Past negative (nakatta)失神しなかった(しっしんしなかった)
polite (masen deshita)失神しませんでした(しっしんしませんでした)
Te form失神して(しっしんして)
Potential失神できる(しっしんできる)
Passive失神される(しっしんされる)
Causative失神させる(しっしんさせる)
Causative passive失神させられる(しっしんさせられる)
Conditional (ba)失神すれば(しっしんすれば)
tara失神したら(しっしんしたら)
Volitional失神しよう(しっしんしよう)
polite (mashou)失神しましょう(しっしんしましょう)
Imperative失神しろ(しっしんしろ)

Common forms generated by rule; see the senses for honorific or irregular usage.

Synonyms & antonyms
  • Synonym気絶きぜつNeutralThe everyday word for briefly passing out, common in speech. 「失神」 leans medical and written, and can also mean clouded consciousness.
  • Synonym昏倒こんとうWrittenWritten word: fainting and falling to the ground, stressing the collapse, while 「失神」 stresses the loss of consciousness itself.
  • Synonym卒倒そっとうWrittenWritten word for suddenly fainting and falling, as in 「卒倒しそうになる」; carries a nuance of suddenness.
  • Antonym正気しょうきNeutralBeing conscious and in one's right mind; the opposite of 「失神」.
  • Antonym意識清明WrittenMedical term for clear consciousness; the opposite of 「失神」.

To pass out, everyday speech uses 「気絶」; 「失神」 is the medical term, as in 「失神発作」. For collapsing to the ground use 「昏倒」 or 「卒倒」; for being conscious use 「正気」.

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

Japanese definitions
  1. 正気せいきを失うしなうこと。喪神そうしん。
  2. 急激きゅうげきな恐怖きょうふや外部がいぶからの攻撃こうげきなどにより、一時的いちじてきに意識いしきを失うしなうこと。
Kanji in this word

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