発生|はっせいhassei[0]heiban (flat)

1. noun, suru verb, intransitive verboccurrence; incidence; outbreak; birth (e.g. of civilization)
2. noun, suru verb, transitive verb, intransitive verbgeneration (of power, heat, etc.); production
   一酸化炭素いっさんかたんそとは炭素たんそ化合物かごうぶつの不完全ふかんぜん燃焼ねんしょうで発生はっせいする有害ゆうがい物質ぶっしつです。↗

   Carbon monoxide is a poisonous substance formed by the incomplete combustion of carbon compounds.
3. noun, suru verb, intransitive verb, biologyontogeny; development; growth; breeding

• Synonym起こるおこるNeutralThe everyday verb for things happening; more common in speech than 「発生」, which leans formal and is typical for accidents and disasters.
• Synonym起きるおきるNeutralCovers occurrence, usually of unwelcome incidents, but also getting up and waking up; very common in everyday speech.
• Synonym生ずるしょうずるWrittenThe older, literary form of 「生じる」; means to produce or give rise to something and leans toward written or formal language.
• Synonym生じるしょうじるWrittenVerb for producing or giving rise to problems and changes, as in 「誤差が生じる」; leans toward written style.
• Synonym出来しゅったいWrittenWritten word for events occurring, read 「しゅったい」; rare today — 「発生」 or 「起こる」 is what you would normally say.
• Synonym出現しゅつげんNeutralNoun for new people or things appearing on the scene, as in 「新人の出現」; stresses the act of emerging rather than events happening.
• Synonym生起せいきWrittenWritten-style word for events taking place; rare in modern Japanese, where 「起こる」 is the everyday choice.
• Related持ち上がるもちあがるNeutralSays a problem or issue has suddenly come up, as in 「問題が持ち上がる」; common in conversation.
• Related沸き起こるわきおこるNeutralFor applause or emotions bursting out all at once; the focus is on things welling up, and it is used mostly with feelings.
• Related発するはっするWrittenTo emit or let out sound, light, heat, or orders; leans written, with the focus on sending something out rather than it arising.
• Related芽生えるめばえるNeutralMeans to bud or sprout, and figuratively for feelings starting to grow, as in 「恋が芽生える」.
• Related湧き上がるわきあがるNeutralFor emotions or cheers surging up, as in 「歓声が湧き上がる」; it covers surging feelings rather than events occurring.
• Antonym消滅しょうめつWrittenWritten-style noun for things vanishing or dying out; the opposite pole to 「発生」.
• Antonym終息しゅうそくWrittenNoun for an epidemic or situation dying down and coming to an end; the counterpart to 「発生」.

Use 「発生」 for accidents, disasters and problems occurring, or for heat and electricity being generated, as in 「事故が発生する」「熱が発生する」. In everyday speech prefer 「起こる」 or 「起きる」; for new things appearing use 「出現」, and for a situation dying down use 「終息」.

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

1. 新あたらしい物事ものごとが生うまれたり起おこったりすること。
2. （生物学せいぶつがく）多た細胞さいぼう生物せいぶつの個体こたいや器官きかんが形成けいせいされる過程かてい。