当初|とうしょtousho[1]atamadaka (head-high)

1. no-adjectivebeginning; start; outset
   その会合かいごうは当初とうしょの予定よていどおりに開催かいさいされた。↗

   The meeting was held as intended at the outset.
2. noun, adverbat first; at the beginning; initially; originally
   当初とうしょ抗議こうぎする人ひとはほんのわずかだったが、今いまやそこらじゅうから湧き起わきおこっている。↗

   At first only a few people protested, but now they're all coming out of the woodwork.

• SynonymはじめNeutralThe most general word for a beginning or start. 「当初」 specifically frames the initial plan or state in contrast with what came later.
• Synonym最初さいしょNeutralMeans the very first or number one. 「当初」 highlights the initial point or state set against how things later turned out.
• Synonym冒頭ぼうとうNeutralThe opening of a piece of writing or a speech. 「当初」 is about the earliest point in time, not the opening of a text.
• Synonym初期しょきNeutralThe early stage or period of something. 「当初」 stresses the initial plan or state in contrast with what followed.
• Synonym序盤じょばんNeutralThe early phase of a game or of something that runs for a while, set against the middle and end. 「当初」 stresses the initial point against later ones.
• Synonym初頭しょとうNeutralThe beginning of a century or era. 「当初」 refers to the start of a particular matter or undertaking.
• Related始まりはじまりNeutralA beginning or origin, as in 「物語の始まり」. 「当初」 stresses the initial time or plan viewed against later developments.
• RelatedスタートNeutralLoanword for starting something or setting off, centred on the act itself. 「当初」 refers to the initial stage or state contrasted with later.
• Related開始かいしNeutralThe start of an action, as in 「試合開始」. 「当初」 focuses on the earliest period rather than the act of beginning.
• RelatedキックオフNeutralLoanword for a kickoff or the launch of a project. 「当初」 simply points to the initial stage or state.
• Related幕開けまくあけNeutralFiguratively the dawn or unveiling of a new era or season. 「当初」 points to the initial period of a matter.
• Related開幕かいまくNeutralThe opening of a performance or event, as in 「開幕戦」. 「当初」 refers to the earliest period rather than the opening itself.
• Related発足ほっそくNeutralThe formal launch of an organization or body, as in 「新内閣の発足」. 「当初」 covers the initial period of anything.
• RelatedビギニングNeutralLoanword for a beginning; rare outside titles. In everyday speech 「最初」 is the natural choice.
• Related滑り出しすべりだしNeutralHow things go right out of the gate, as in 「好調な滑り出し」; it rates the start. 「当初」 marks the initial stage against later ones.
• Related出だしでだしNeutralThe opening or first moves, also the start of a song, as in 「出だしは順調」. 「当初」 stresses the initial stage or state versus later.
• Related幕開きまくあきNeutralThe rise of the curtain; the opening of a play or event. 「当初」 is about the earliest period contrasted with later.
• Related仰けのっけCasualColloquial, mostly as 「のっけから」, meaning right from the very start. 「当初」 is more formal.
• Antonym終盤しゅうばんNeutralAntonym: the final stage of a game or undertaking, standing at the end where 「当初」 stands at the beginning.
• Antonym最終さいしゅうNeutralAntonym: last or final, the very end. It sits opposite 「当初」 on the start-to-finish axis.

Use 「当初」 for the initial plan or period set against what came later, as in 「当初の予定」 or 「当初は反対だった」. For a plain beginning pick 「最初」 or 「始め」; for an early stage, 「初期」. 「スタート」「開始」「キックオフ」 focus on the act of starting; 「冒頭」 is for openings of texts and speeches; 「序盤」 covers early phases of games; 「初頭」 marks the start of centuries and eras; 「滑り出し」「出だし」 rate how a start goes; 「幕開き」「幕開け」「開幕」「発足」 suit openings and launches; 「仰け」 is colloquial. Antonyms: 「終盤」「最終」.

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

1. 物事ものごとの初はじめ。副詞ふくし的てきにも用もちいる。