大部分|だいぶぶんdaibubun

1. nounmost part; greater part; majority
   石炭せきたんは大部分だいぶぶんが炭素たんそから成なっている。↗

   Coal consists mostly of carbon.

• Synonym大半たいはんNeutralA part far beyond half; fits both speech and writing and is so close to 「大部分」 that the two are usually interchangeable.
• Synonym大多数だいたすうNeutralThe great majority of people or things, with the emphasis on sheer number; 「大部分」 can also cover quantity or portion of a whole.
• Synonym大方おおかたNeutralMeans mostly or probably and works adverbially to express conjecture; 「大部分」 stays with the proportion of a whole.
• SynonymたいていNeutralAn adverb meaning mostly or usually, centred on frequency; 「大部分」 is about quantity and proportion instead.
• Synonym過半かはんWrittenWritten/formal prose for more than half, common in official documents, as in 「過半を占める」.
• Synonym大概たいがいNeutralAn adverb for mostly or generally; it can also tell someone not to overdo it, as in 「大概にしろ」.
• SynonymほとんどNeutralAn adverb meaning almost all; with a negative it means hardly or barely. 「大部分」 is a noun and implies a slightly lower share.
• Related過半数かはんすうNeutralMore than half of a total; the usual choice for votes and ballots, stressing the point where the half line is crossed.
• Related多数たすうNeutralLarge numbers of people or things, as in 「多数決」; 「大部分」 instead stresses the proportion within a whole.
• Antonym一部いちぶNeutralA part or portion of a whole — the opposite of 「大部分」, which denotes the majority share.
• Antonym少数しょうすうNeutralA small number or minority, standing against both 「大部分」 and 「多数」.

Default to 「大部分」 for the greater part of a whole. 「大半」 is near-interchangeable; pick 「過半数」 for crossing the half mark in a vote, 「多数」 for large numbers of people, 「殆ど」 for almost all, 「大抵」 for usually, and 「一部」 for a mere part; 「過半」 is formal written prose.

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

1. ほぼ全部ぜんぶ。多おおくの部分ぶぶん。