Definition of focus in English:

focus

Line breaks: focus
Pronunciation: /ˈfəʊkəs
 
/

noun (plural focuses or foci /ˈfəʊsʌɪ/)

1The centre of interest or activity: this generation has made the environment a focus of attention
More example sentences
  • But combine it with a programme that lacks a clear focus and Cork's year in the cultural spotlight is already looking shaky.
  • Once you have a clear focus, gather the right team around you to get the job done.
  • But if it keeps a clear focus it might achieve a way forward for our embattled province.
Synonyms
centre, focal point, central point, centre of attention, hub, pivot, nucleus, heart, cornerstone, linchpin, kingpin, bedrock, basis, anchor, backbone, cynosure
1.1An act of concentrating interest or activity on something: our focus on the customer’s requirements
More example sentences
  • To be charitable, perhaps his paranoid focus on who'd been criticising Latham obscured his focus.
  • Focus on your own feelings and share them with your partner, so you won't lose the focus of your own body.
  • I relish the hours when my entire focus isn't concentrated on breathing.
Synonyms
emphasis, accent, priority, attention, concentration
substance, essence, gist, matter
1.2 Geology The point of origin of an earthquake. Compare with epicentre.
More example sentences
  • The geographic point directly above the focus is called the earthquake epicenter.
  • This result strongly agrees with the upward migration of seismic foci in the volcanic edifice, which has been found to precede recent flank eruptions.
1.3 Medicine The principal site of an infection or other disease.
More example sentences
  • There was extensive embolization to the brain and multiple foci of Aspergillus infection in kidneys and adrenal glands.
  • An identifiable focus of primary infection should also be addressed when possible.
  • The macroscopically apparent thrombosed vessels in case 3 contained tumor emboli and multiple foci of infarction.
2 [mass noun] The state or quality of having or producing clear visual definition: his face is rather out of focus figurative the incident brought her feelings for Alexander sharply into focus
More example sentences
  • It's only to be expected that most of the pictures are not of the highest quality, often out of focus or a bit blurred.
  • When she finally did open them, everything blurred out of focus, then came in clear.
  • I'm definitely one of those people who hears most music as a soundtrack to a film going on somewhere in my head, usually deeply out of focus.
Synonyms
2.1 another term for focal point.
More example sentences
  • While Zippy has the attention span of a goldfish, his wife has the focus of an electron microscope.
  • The probability for such an event occurring is only significant at the plane of focus, where photon flux is the highest.
  • Their focus was always upon the general rather than the particular.
2.2 [count noun] The point at which an object must be situated with respect to a lens or mirror for an image of it to be well defined.
More example sentences
  • In the Nasmyth focus, an oblong tertiary mirror is positioned in this opening and it reflects the light from the secondary mirror to foci located on either side of the telescope.
  • The problems with the microlens array design are low light throughput, non-uniform intensity foci, and lens aberrations.
  • There is a central hole in the main mirror through which the light passes and is brought to a focus by an eyepiece lens.
2.3 [count noun] A device on a lens which can be adjusted to produce a clear image.
More example sentences
  • He adjusts the focus of the Carl Zeiss 120 mm macro lens, which allows him to work very close up.
  • These lenses adjust their focus with a patient's eye muscles to give them seamless near or distance vision.
  • The focus can be adjusted slightly in order to sharpen up different parts of the image corresponding to objects at different depths in the scene.
3 Geometry One of the fixed points from which the distances to any point of a given curve, such as an ellipse or parabola, are connected by a linear relation.
More example sentences
  • The circumcircle of a triangle formed by three tangents to a parabola, passes through the focus of the parabola.
  • The focus and directrix of a parabola were considered by Pappus.
  • The catenary is the locus of the focus of a parabola rolling along a straight line.
4 Linguistics An element of a sentence that is given prominence by intonational or other means.

verb (focuses, focusing, focused or focusses, focussing, focussed)

[no object] Back to top  
1Adapt to the prevailing level of light and become able to see clearly: try to focus on a stationary object
More example sentences
  • His blue eyes didn't seem to focus on any one person on the floor below him, but seemed to see all of them without focusing.
  • She could only see a blur at first, but her vision focused and she was able to see clearly her surroundings.
  • When she was able to focus, she saw two vamps descending on her.
1.1 [with object] Cause (one’s eyes) to focus: she focused her eyes on his face
More example sentences
  • Feeling distinctly sick, he lay back down and focused his eyes, surveying his surroundings.
  • Every few metres the cat stopped and twisted its head around, focussing its yellow eyes on me, checking to see if I was still in pursuit.
  • I think some of the brain which attends to focussing my eyes may have leaked out.
1.2 [with object] Adjust the focus of (a telescope, camera, or other instrument): they were focusing a telescope on a star
More example sentences
  • For example, in one puzzle you have to focus a telescope, and to do so you have to add or remove 14 lenses.
  • I have written about this many times, but modern auto-focus cameras deliver more ‘out of focus’ shots than manually focussed cameras.
  • ‘Just look at me,’ says Juergen, focusing the camera.
Synonyms
bring into focus, bring to a focus;
aim, point, turn
1.3(Of rays or waves) meet at a single point.
More example sentences
  • These scatter the sun's rays, and prevent them from being focused together into a single bright point.
  • In narrow inlets and coves, the wave can become focused or amplified, reaching tens of metres in height.
  • Because gamma rays are hard to focus into sharp images, the science team then used the X-ray telescope on Swift to determine a precise location.
1.4 [with object] (Of a lens) make (rays or waves) meet at a single point.
More example sentences
  • When a lens system optimally focuses an incoming ray bundle, the spread of passed wavelengths is in focus at a range of points in front of, on, and behind the sensor focal plane.
  • When a lens is used to focus the sun's rays onto a piece of paper the distance of the paper from the lens is called the focal length.
  • And they were used for starting fires by focusing the rays of the sun.
1.5 [no object] (Of light, radio waves, or other energy) become concentrated into a sharp beam.
More example sentences
  • It works like your grappling hook did, but instead of string, it uses gravity focused into a ‘beam’ to connect it.
  • In that time, the energy had focused and spiked beyond what I have ever felt before.
  • Normally a light beam will focus to a point no smaller than about the size of the light's wavelength.
1.6 [with object] (Of a lens) concentrate (light, radio waves, or energy) into a sharp beam.
More example sentences
  • An objective lens focuses the light onto a region approximately 1 mm in diameter and subsequently collects the light returning from the target.
  • The eye has a lens, and even ‘film’ (the retina), which detects light focused by the lens.
  • In the simple experiment, a converging lens focuses laser light from two pinholes onto two different photodetectors.
2 (focus on) Pay particular attention to: the study will focus on a number of areas in Wales
More example sentences
  • As his heart started to race, he drew his attention inward, focussing on his breathing.
  • The study focussed on a period of time beginning four years before the casino opened and four years after.
  • More studies focusing on this particular problem are needed before a conclusion can be drawn.
2.1 [with object] Concentrate: an opportunity to focus research on the health needs of the population
More example sentences
  • He concentrated, focusing his thoughts on the strange impressions he was receiving.
  • According to dharma, or divine law, temple worship is important because it focuses our concentration on God.
  • The concentration on punishment damages the national debate by focussing all attention on revenge.
Synonyms
concentrate, fix, centre, pivot, zero in, zoom in;
address itself to, pay attention to, pinpoint, spotlight, revolve around, have as its starting point
2.2 [with object] Linguistics Place the focus on (an element of a sentence).

Origin

mid 17th century (as a term in geometry and physics): from Latin, literally 'domestic hearth'.

Derivatives

focuser

noun
More example sentences
  • Along with its atom stream turrets on port and starboard sides there are energy focusers to destroy anything under atmosphere.
  • He had two focusers floating on ether side of his head to represent his constant control.
  • A helical focuser is located at the rear of the body.

Definition of focus in:

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