主催（しゅさい、shusai）
- organizer

The Japanese word 主催 しゅさい means "sponsorship," "hosting," "organization," or "to organize." It refers to the act of planning, managing, and taking responsibility for an event, activity, or project. This includes handling the logistics, finances, and overall execution of the undertaking. The person or entity that does this is the 主催者 しゅさいしゃ, which translates to "organizer" or "sponsor." 主催 can be used as a noun or a verb (in a modified form). It implies a leading role in the operation of something.

⚫︎イベントの主催 Translation: The sponsorship of the event ⚫︎大学がセミナーを主催する Translation: The university hosts the seminar. ⚫︎この展覧会の主催は美術館です。 Translation: The sponsor of this exhibition is the art museum.

⚫︎You'd use 主催 when discussing who is responsible for putting on an event. ⚫︎It's common to see 主催 listed on event posters, websites, or programs to indicate the organizing entity. ⚫︎When used as a verb, it takes the particle を before the event name, and often uses a form such as 主催する or 主催しました (past tense).

⚫︎The word 主催 is typically written in kanji 主催 and read しゅさい. ⚫︎The hiragana reading しゅさい never changes. ⚫︎There are no variations in okurigana.

⚫︎主催者 しゅさいしゃ (organizer/sponsor) ⚫︎開催 かいさい (holding/staging - often used for events) ⚫︎運営 うんえい (management/operation) ⚫︎企画 きかく (planning/project) ⚫︎後援 こうえん (sponsorship/support - often used in combination with other words)

⚫︎共催 きょうさい (co-sponsorship) ⚫︎There is no single direct antonym. Often, it would be someone else acting as 主催.

このコンサートの主催は、地元の音楽団体です。 ・Translation: The sponsor of this concert is the local music group. ・Explanation: This sentence clearly identifies the group responsible for organizing the concert.

来年のオリンピックは、日本が主催します。 ・Translation: Japan will host next year's Olympics. ・Explanation: This shows how 主催 is used in the context of a large-scale event.

The word 主催 is a combination of two kanji: 主 (しゅ) meaning "main," "principal," or "chief," and 催 (さい) meaning "to hold," "to organize," or "to urge." Therefore, 主催 indicates the "main" or "principal" organization or holding of an event.