subfield

/ˈsəb-ˌfēld/ (ame, mw)

subfield — noun

1. a particular area of study or research that forms a smaller, more focused part o

1.名詞C1
釋義

a particular area of study or research that forms a smaller, more focused part of a larger academic discipline — for example, bioinformatics is a subfield of biology, and behavioural economics is a subfield of economics.

例句

Omar decided to specialise in astrophysics, a subfield of physics that studies stars and galaxies.

subfield + of + [broader field] for specialisation

Computational linguistics is a growing subfield that sits between computer science and language studies.

subfield described with 'growing' + preposition 'between'

同義詞
  • specialty

    more common in US English; often used for medical or professional fields rather than academic branches

  • branch

    broader and less formal; can refer to any division of knowledge or an organisation

  • discipline

    larger in scope than a subfield; a subfield belongs to a discipline

反義詞
  • field

    the broader area that contains the subfield

文法句型

subfield + of + [broader field]

用法筆記

Often paired with 'within' or 'of' to name the larger discipline. The word implies a recognised, organised branch of study rather than a temporary research interest.

常見錯誤

Bioinformatics is a small subfield of biology.
Bioinformatics is a subfield of biology.
💡Do not add 'small' unless size is relevant; 'subfield' already implies a part of a larger field.

2. a number system contained inside a larger number system (such as the rational nu

2.名詞C2
釋義

a number system contained inside a larger number system (such as the rational numbers inside the real numbers) and using the same addition and multiplication rules, while still obeying all the algebraic laws that define a field.

例句

Professor Chen asked her algebra class to verify that the rational numbers are a subfield of the real numbers.

subfield + of + [set] + 'verify that' with that-clause

In algebra class, Yuki proved that the Gaussian integers are not a subfield of the complex numbers.

文法句型

subfield + of + [mathematical field]

用法筆記

A strictly technical term in abstract algebra. The subfield must be closed under the same field operations as the larger field — it is not just any subset. Distinguish from a 'subring', which does not require multiplicative inverses.

常見錯誤

The integers are a subfield of the rational numbers.
The integers are a subring, not a subfield, of the rational numbers
💡they lack multiplicative inverses for most elements.' — A subfield must be closed under division; the integers fail this condition.