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.
The Sahara Desert is a vast region.
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.
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.
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.
Emphasizing that something is so large it cannot be measured, often used for abstract concepts like a vast difference or vast expanse of time.
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'.
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.
The vast desert stretched endlessly.
The project cost a vast amount of money.
He amassed a vast fortune.
Used for enormous volumes of data, information, documents, or work. Implies a massive, often overwhelming quantity.
We need to analyze a vast amount of data.
He has a vast knowledge.
Often used for abstract things like influence, effort, or contribution. More formal than 大きな.
The discovery had a vast influence on science.
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.
A vast number of stars were shining in the night sky.
Means 'extraordinary', 'immense', or 'absurdly large'. Conveys a sense of being beyond comprehension. Used for vast distances, differences, or amounts.
There is a vast difference between the two.
The size of the universe is vast beyond measure.
Literally 'immeasurable'. Used for vast potential, influence, or loss. More formal and often found in written language.
The impact of the accident is vast and immeasurable.
Means 'infinite' or 'limitless'. Can be used for vast possibilities or space, but is more absolute than 'vast'.
The universe has a vast, infinite expanse.
The bill was passed by a vast majority.
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.
He enjoys the vast trust of his employees.
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.