English · Word Candidate

focus

/ˈfəʊ̯.kəs/

Proposed by a contributor, not yet supported by evidence.

Also seen as: foci · focuses · focusses · focusing

Sense 1

Both English Tiếng Việt

Meaning · English

A point at which reflected or refracted rays of light converge.

Nghĩa · Tiếng Việt

điểm mà tia sáng bị phản xạ hoặc khúc xạ hội tụ

Machine-translated — suggest a fix

Noun

Examples

The heat of sunlight at the focus of a magnifying glass can easily set dry leaves on fire.

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

Both English Tiếng Việt

Meaning · English

A point of a conic at which rays reflected from a curve or surface converge.

Nghĩa · Tiếng Việt

điểm trên hình nón mà tia sáng phản xạ từ đường cong hoặc bề mặt hội tụ

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

Both English Tiếng Việt

Meaning · English

To cause (rays of light, etc) to converge at a single point.

Nghĩa · Tiếng Việt

làm cho tia sáng hội tụ tại một điểm

Machine-translated — suggest a fix

Verb

Examples

The difficulties of focussing colour-light signals on curved tracks to ensure maximum sighting distance were underlined in the recent official report [...] on a low-speed collision at Newcastle Central on July 25, 1960, between an unfitted freight and a diesel-hauled passenger train.

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 4

Both English Tiếng Việt

Meaning · English

To adjust (a lens, an optical instrument) in order to position an image with respect to the focal plane.

Nghĩa · Tiếng Việt

điều chỉnh (thấu kính, dụng cụ quang học) để đặt hình ảnh với mặt phẳng tiêu cự

Machine-translated — suggest a fix

Verb

Examples

You'll need to focus the microscope carefully in order to capture the full detail of this surface.

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 “focus” mean?

A point at which reflected or refracted rays of light converge.

Is “focus” formal or informal?

No register label has been reviewed yet — treat it as neutral and check the usage notes above.