Translation guide
The English word 'vast' describes something extremely large in area, extent, or scope. In Japanese, the best translation depends on what is being described: physical space, abstract range, or quantity. Common adjectives include 広大な (kōdai na) for physical expanses, 莫大な (bakudai na) for huge amounts, and 膨大な (bōdai na) for enormous volumes of data or work. For emphasis, 途方もない (tohō mo nai) conveys a sense of being immeasurable.
Describing a very large area or expanse, such as a desert, ocean, or universe.
The most common and neutral adjective for vast physical spaces. Used for landscapes, oceans, and the universe.
サハラ砂漠は広大な地域です。
The Sahara Desert is a vast region.
広大な宇宙には無数の星がある。
There are countless stars in the vast universe.
Emphasizes a sense of openness and spaciousness, often with a positive connotation. Suitable for describing comfortable, open areas.
広々とした公園でピクニックをした。
We had a picnic in the vast park.
Literary and somewhat poetic, implying a boundless, featureless expanse. Often used for deserts or oceans in written language.
茫漠とした砂漠がどこまでも続いていた。
The vast desert stretched endlessly.
Describing something that is huge in quantity, such as a vast sum of money, vast amounts of data, or vast knowledge.
Primarily used for huge sums of money, wealth, or costs. Can also be used for enormous effort or influence.
そのプロジェクトには莫大な費用がかかった。
The project cost a vast amount of money.
彼は莫大な財産を築いた。
He amassed a vast fortune.
Used for enormous volumes of data, information, documents, or work. Implies a massive, often overwhelming quantity.
膨大なデータを分析する必要がある。
We need to analyze a vast amount of data.
彼は膨大な知識を持っている。
He has a vast knowledge.
Often used for abstract things like influence, effort, or contribution. More formal than 大きな.
その発見は科学に多大な影響を与えた。
The discovery had a vast influence on science.
Emphasizing that something is so large it cannot be measured, often used for abstract concepts like a vast difference or vast expanse of time.
Means 'extraordinary', 'immense', or 'absurdly large'. Conveys a sense of being beyond comprehension. Used for vast distances, differences, or amounts.
両者の間には途方もない違いがある。
There is a vast difference between the two.
宇宙の大きさは途方もない。
The size of the universe is vast beyond measure.
Means 'infinite' or 'limitless'. Can be used for vast possibilities or space, but is more absolute than 'vast'.
宇宙は無限の広がりを持っている。
The universe has a vast, infinite expanse.
Used to emphasize the extent of a feeling or the size of a majority.
A straightforward and natural way to say 'vast' when modifying nouns like 'majority' or 'relief'. It literally means 'very big'.
その法案は非常に大きな多数で可決された。
The bill was passed by a vast majority.
それを聞いて非常に大きな安堵感を覚えた。
I felt a vast sense of relief upon hearing that.
Means 'tremendous' or 'immense'. Often used for trust, support, or power. Slightly more emphatic than 非常に大きな.
彼は社員から絶大な信頼を得ている。
He enjoys the vast trust of his employees.
These three are often confused. 広大な (kōdai na) is for physical area (vast land). 莫大な (bakudai na) is for money or cost (vast sum). 膨大な (bōdai na) is for volume of data or work (vast amount of information). Using the wrong one can sound unnatural.
広大な敷地 (vast grounds) / 莫大な借金 (vast debt) / 膨大な書類 (vast pile of documents)
広大な敷地 (vast grounds) / 莫大な借金 (vast debt) / 膨大な書類 (vast pile of documents)
While 広い (hiroi) means 'wide' or 'spacious', it is not strong enough to convey 'vast'. Use 広大な or other emphasized adjectives unless the context is casual and the vastness is not extreme.
An i-adjective meaning 'a vast number of' or 'countless'. Often used for large quantities of things like stars, casualties, or mistakes. Can sound literary or emphatic.
夜空にはおびただしい数の星が輝いていた。
A vast number of stars were shining in the night sky.
Literally 'immeasurable'. Used for vast potential, influence, or loss. More formal and often found in written language.
その事故の影響は計り知れない。
The impact of the accident is vast and immeasurable.