optional
Proposed by a contributor, not yet supported by evidence.
Also seen as: optionals
Sense 1
Not compulsory; left to personal choice; elective.
Adjective
Examples
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).
Sense 2
Something that is not compulsory, especially part of an academic course.
điều gì đó không bắt buộc, đặc biệt là phần của khóa học học thuật
Machine-translated — suggest a fix
Noun
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).
Sense 3
In various programming languages, a kind of variable that is assigned a specific data type but may or may not hold an actual value.
một loại biến được gán kiểu dữ liệu cụ thể nhưng có thể hoặc không chứa giá trị thực
Machine-translated — suggest a fix
Noun
Examples
Usage example from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01)
Sources & notes
Adapted from English Wiktionary (CC BY-SA 4.0, retrieved 2026-08-01 via kaikki.org).
Common questions
What does “optional” mean?
Not compulsory; left to personal choice; elective.
Is “optional” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.