focus

Less common meanings

4. 4
   sharpnessnoununcountable

   The sharpness of an image, produced when light from a scene meets exactly on the film or sensor; being in 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.

   UsageSet phrases: in focus, out of focus, come into focus; also sharp focus or soft focus.

   Similarsharpness, clarity, definition

   Note

   Because it is a matter of degree, it can change within a shot, and a film scene can carry a boy's face gradually from soft into sharp focus. Source

   Checked 1 Nov 2026 · 1 fact

   • Focus can change gradually within a shot, bringing a face into sharp focus. usa.canon.com
5. 5
   verbintransitive

   Of a person, lens or camera, to adjust so that the image becomes sharp and clear.

   Modern lenses focus almost instantly on a moving subject.

   The camera focused before the bird flew away.

   UsageOften used with on: the camera focuses on the face, my eyes took a moment to focus.

6. 6
   nouncountable

   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.

   Adjusting the telescope brought the starlight to a sharp focus.

   Each lens directs the beams toward a common focus on the sensor.

   UsageThe plural is foci or focuses.

7. 7
   gather lightverbtransitive

   To cause rays of light or similar energy to converge at a single point.

   A magnifying glass can focus sunlight into a tiny spot bright enough to scorch paper.

   The instrument focused the laser onto the target.

   Similarconcentrate, direct

   Oppositescatter, diffuse, disperse

   Note

   The picture behind the verb is a fire. Latin focus meant 'hearth', the same word behind its relative fuel, and Kepler brought it into the sciences in his writing on optics and on the geometry of curves. The verb takes light or a light-like beam as its object: Trains Illustrated in 1961 wrote of the difficulty of focussing signal lights on curved track. The doubled spelling focussing appears alongside focusing. Source

   Checked 30 Oct 2026 · 3 facts

   • Latin focus meant “hearth” and is also an ancestor of fuel. en.wiktionary.org
   • Kepler introduced the scientific term in his treatment of conic sections within a work on optics. mathshistory.st-andrews.ac.uk
   • Trains Illustrated discussed the difficulty of focussing signal lights on curved tracks in 1961. en.wiktionary.org
8. 8
   earthquake originnouncountable

   The exact underground point where an earthquake originates, located directly below the epicenter.

   Seismographs helped pinpoint the focus several kilometers beneath the valley.

   A shallow focus often produces more surface damage than a deep one.

   Similarhypocenter

   Note

   Seismology's point lies underground, where an earthquake begins, and it is located in three dimensions, depth included. A focus can be shallow or deep, and its depth strongly influences how hard the ground shakes overhead. Source

   Checked 1 Nov 2026 · 4 facts

   • The focus is the underground point where an earthquake begins. en.wikipedia.org
   • The focus is located in three dimensions, including depth. usgs.gov
   • Earthquake foci can be shallow or deep. usgs.gov
   • Focal depth strongly affects shaking at the surface. usgs.gov
9. 9
   geometrynouncountable

   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.

   In an ellipse, light leaving one focus reflects to the other focus.

   A parabola has a single focus where parallel rays gather after reflection.

   Note

   Kepler carried the word into mathematics in his writing on optics, before he showed that planets move in ellipses, making it the geometer's version of the optical point. The geometry keeps the optics: put a light at one focus of an ellipse and its rays, reflected off the curve, meet at the other. A parabola has a single focus, where rays parallel to its axis gather. Source

   Checked 30 Oct 2026 · 5 facts

   • Kepler introduced the mathematical term focus in his work on optics. mathshistory.st-andrews.ac.uk
   • Kepler's introduction of focus in optics preceded his discovery that planetary orbits are elliptical. en.wikipedia.org
   • An ellipse reflects rays from one focus through the other, connecting the geometric focus with optical focusing. opentext.uleth.ca
   • A parabola has one focus. en.wikipedia.org
   • Rays arriving parallel to the parabola's axis gather at its focus after reflection; mutual parallelism alone is insufficient. amsi.org.au
10. 10
    active state (screen)nouncountable or uncountable

    The state of being the active element in a user interface, ready to receive input and usually shown by a visual highlight.

    Pressing Tab moves focus from one field to the next.

    When the dialog opens, focus jumps to the first text field.

    Note

    In interface design only one element holds it at a time, so it often takes the article: a component "has the focus", and typed or pasted input goes wherever it sits. Without the article it moves like a token passed along, as when Tab moves focus to the next field. The matching verb names the act of handing it over. Source

    Checked 30 Oct 2026 · 3 facts

    • Only one element holds keyboard focus at a time. w3.org
    • Focus directs keyboard events, but text insertion requires an editable target; focusing a non-editable element does not make it accept pasted text. w3.org
    • Tab moves focus forward through focusable elements. w3.org
11. 11
    make active (screen)verbtransitive

    To transfer input to a visual element so that it receives subsequent keystrokes and other input.

    Developers can focus any element by calling the appropriate method.

    The script focuses the username field as soon as the page loads.

    Note

    The programmer's verb, the active counterpart of the interface noun: to focus a text box is to give it the focus so that it receives the keystrokes that follow. It takes a direct object, and code often focuses a field explicitly, since otherwise the user's typing goes elsewhere. Doing so typically fires focus-change events and moves the visible highlight. Source

    Checked 30 Oct 2026 · 4 facts

    • A focused text box receives subsequent keyboard events. html.spec.whatwg.org
    • Code can explicitly give an element keyboard focus. learn.microsoft.com
    • Changing focus fires focus-related events. developer.mozilla.org
    • Focusing a field typically changes its visible focus indication, although visibility depends on browser behavior. developer.mozilla.org
12. 12
    nouncountablemedicine

    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.

    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.

    Note

    Clinical writing keeps the Latin plural here: reports speak of foci rather than focuses, and the word usually takes of, as in a focus of infection or several foci of disease. Its adjective, focal, marks a problem that starts in or is limited to one spot, as in a focal lesion or a focal seizure. Source

    Checked 31 Oct 2026 · 3 facts

    • Foci is the Latin plural form of focus. en.wiktionary.org
    • Focal describes disease limited to one particular area. training.seer.cancer.gov
    • A focal seizure has a localized origin, although it can spread. epilepsydiagnosis.org
13. 13
    noun

    The word or phrase in a sentence or passage that carries the most important or newest information.
14. 14
    noun

    An object used by a spellcaster to concentrate or channel power when working a magic spell.
15. 15
    noun

    The central point of a fish's scale, from which the scale began growing when the fish was young.
16. 16
    verbobsolete

    To total up the figures recorded in a set of accounts.

    Whole pages of it are filled with masses of figures, generally single numbers added up in batches, and then the totals added in batches again, as though he were "focusing" some account, as the auditors put it.

    1897, Bram Stoker, Dracula