How to say "commencement" in Japanese

• 開始かいしJLPT N3approx.Common
  noun, suru verb, transitive verb, intransitive verbCovers the general sense of 'commencement' as the beginning of an activity, process, or event. It is the default choice when you mean that something starts, rather than a ceremony or the workday.
  何時いつに搭乗とうじょう開始かいしですか。↗

  What time does boarding begin?
• 始業しぎょうCommon
  noun, suru verb, intransitive verbRefers to 'commencement' only as the start of work, such as the beginning of the working day; for starting an activity or event in general it is not the word you want.
  教室きょうしつに入はいって席せきに着つくのとほぼ同時どうじに、始業しぎょうを知しらせるチャイムの音おとが鳴り響なりひびく。↗

  About the same time as he entered the classroom and arrived at his seat, the chime to announce class rings across the school.
• 卒業式そつぎょうしきCommon
  nounMatches 'commencement' in the sense of the graduation ceremony itself, as in American English usage; it refers only to the ceremonial event, not to the start of an activity or process.
  卒業式そつぎょうしきは二にヶ月かげつ先さきだ。↗

  The graduation is two months ahead.
• 口切りくちきりCommon
  nounReally means broaching a subject or an opening remark — the first mention of a topic in conversation. As a rendering of 'commencement' it is marginal; seldom the word you want for a general start.

Use 開始 for the beginning of an activity or process, 始業 for the start of work, 卒業式 for the graduation ceremony, and 「口切り」 only for broaching a subject or opening remarks.

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

• 開始かいしstart
• 始業しぎょうstart of work
• 卒業式そつぎょうしきgraduation ceremony
• 口切りくちきりstart broaching (a subject)
• 仕掛かりしかかりcommencement
• 蓋開けふたあけopening
• とっつきbeginning
• 口開けくちあけbeginning
• 水端みずはなstart
• 仕掛けしかけcommencement