Translation guide
The English word "undefined" is used in technical contexts to describe something that has not been given a definition or value. This guide helps learners express this concept naturally in Japanese, focusing on computing, mathematics, and general usage.
Expressing that something lacks a definition, value, or clear meaning, often in technical or formal contexts.
The most direct and common translation for 'undefined' in technical fields like programming and mathematics. It literally means 'not yet defined'.
Describing something that is not clearly defined, ambiguous, or lacking distinct boundaries in everyday language.
Directly translating 'undefined' as 未定義 in everyday conversation about vague concepts can sound overly technical or unnatural. Use 曖昧 or はっきりしない instead.
この変数は未定義です。
This variable is undefined.
Undefined behavior should be avoided.
A more descriptive phrase meaning 'has not been defined'. Commonly used in explanations or when the passive/state is emphasized.
That function is not defined yet.
Used in mathematics for 'indefinite' or 'undefined', such as in limits or forms like 0/0. More specific than 未定義.
This expression is an indeterminate form.
Means 'ambiguous' or 'vague'. Suitable when 'undefined' refers to unclear boundaries or meanings.
His role is undefined (ambiguous).
A common phrase meaning 'not clear' or 'vague'. Used in spoken Japanese.
The plan is still undefined (unclear).