大部(たいぶ)lengthy (of a book, etc.), voluminous, most (e.g. most part), greater, fairly, a good deal, much

大部(たいぶ)の書類(しょるい)を読(よ)むのは大変(たいへん)だ。

Reading the majority of the documents is tough. {lengthy (of a book, etc.), voluminous, most (e.g. most part), greater, fairly, a good deal, much}

10時間(じかん)かけてこの大部(たいぶ)の本(ほん)を読(よ)みました。

I spent 10 hours reading this massive book. {lengthy (of a book, etc.), voluminous, most (e.g. most part), greater, fairly, a good deal, much}

認知(にんち)症(しょう)のせいで記憶(きおく)の大部(たいぶ)がなくなってしまった。

Due to dementia, a large part of the memory has been lost. {lengthy (of a book, etc.), voluminous, most (e.g. most part), greater, fairly, a good deal, much}

大部(たいぶ)の本(ほん)を読(よ)んだ結果(けっか)、語彙(ごい)力(りょく)が格段(かくだん)に上(あ)がりました。

As a result of reading a lot of books, my vocabulary has significantly improved. {lengthy (of a book, etc.), voluminous, most (e.g. most part), greater, fairly, a good deal, much}

脳卒中(のうそっちゅう)を起(お)こして以来(いらい)、記憶(きおく)の大部(たいぶ)が思(おも)い出(だ)せない事(こと)があります。

Since having a stroke, there are times when I cannot recall most of my memories. {lengthy (of a book, etc.), voluminous, most (e.g. most part), greater, fairly, a good deal, much}