# focus

Pronunciation: say "FOH-kuhs" US /ˈfoʊ.kəs/, UK /ˈfəʊ.kəs/

## Verb

1. To give one's attention, effort or resources to one particular thing, or to concentrate steadily without being distracted.
   - Simple: To give all your attention or effort to one thing, or to concentrate.
   - _The committee chose to focus on housing rather than transit._
   - _Investors are focusing on long-term growth this year._
5. Of a person, lens or camera, to adjust so that the image becomes sharp and clear.
   - Simple: Of a camera, a lens or your eyes, to change so that what you see becomes clear and sharp.
   - _Modern lenses focus almost instantly on a moving subject._
   - _The camera focused before the bird flew away._
7. To cause rays of light or similar energy to converge at a single point.
   - Simple: To make rays of light come together at one point.
   - _A magnifying glass can focus sunlight into a tiny spot bright enough to scorch paper._
   - _The instrument focused the laser onto the target._
11. To transfer input to a visual element so that it receives subsequent keystrokes and other input.
   - Simple: To make an item on the screen the active one, so it receives what you type next.
   - _Developers can focus any element by calling the appropriate method._
   - _The script focuses the username field as soon as the page loads._

## Noun

2. The thing toward which activity, attention, or interest is mainly directed.
   - Simple: The main thing that people pay attention to or care about.
   - _The focus of the investigation shifted to the second suspect._
   - _Education became the campaign's central focus._
3. A state of concentrated attention directed steadily at one thing.
   - Simple: The act of giving all your attention to one thing.
   - _His focus slipped after hours of staring at the screen._
   - _Meditation can improve your focus over time._
4. The sharpness of an image, produced when light from a scene meets exactly on the film or sensor; being in or out of focus.
   - Simple: How sharp and clear a picture is, as in 'in focus' or 'out of focus'.
   - _In the wide shot, even the trees at the edges of the frame were in crisp focus._
   - _Poor focus ruined an otherwise perfect shot._
6. The point where rays of light meet after being reflected by a mirror or bent by a lens, or from which they appear to spread.
   - Simple: The point where light rays meet, or seem to spread from, after passing through a lens or bouncing off a mirror.
   - _Adjusting the telescope brought the starlight to a sharp focus._
   - _Each lens directs the beams toward a common focus on the sensor._
8. The exact underground point where an earthquake originates, located directly below the epicenter.
   - Simple: The exact place underground where an earthquake actually begins.
   - _Seismographs helped pinpoint the focus several kilometers beneath the valley._
   - _A shallow focus often produces more surface damage than a deep one._
9. A fixed point used to define a conic section, such as either of the two points inside an ellipse whose distances to any point on the curve add up to a constant.
   - Simple: A special fixed point used to draw or describe a curve such as an ellipse or a parabola.
   - _In an ellipse, light leaving one focus reflects to the other focus._
   - _A parabola has a single focus where parallel rays gather after reflection._
10. The state of being the active element in a user interface, ready to receive input and usually shown by a visual highlight.
   - Simple: When an item on a screen is the active one, ready to receive what you type or click.
   - _Pressing Tab moves focus from one field to the next._
   - _When the dialog opens, focus jumps to the first text field._
12. A small area of the body, limited to one spot, that is the center of an infection, disease, or abnormal tissue, or the place from which it spreads.
   - Simple: A small spot in the body where an infection, illness, or unhealthy tissue is centered or spreads from.
   - _The scan revealed a single focus of abnormal tissue in the liver, about the size of a pea._
   - _Several foci of infection had developed in the bone, and each one had to be drained._

## Other meanings

- (noun) The word or phrase in a sentence or passage that carries the most important or newest information.
- (noun) An object used by a spellcaster to concentrate or channel power when working a magic spell.
- (noun) The central point of a fish's scale, from which the scale began growing when the fish was young.
- (verb) To total up the figures recorded in a set of accounts.

## Origin

Borrowed from Latin "focus" ("hearth, fireplace"), and related to "fuel." Kepler introduced the term into mathematics in his 1604 work on optics, since light emitted from one focus of an ellipse would reflect and converge at the other.

Source: DictionaryAI, https://dictionaryai.com/define/focus (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).