focus

[foh-kuh s] /ˈfoʊ kəs/
noun, plural focuses, foci
[foh-sahy, -kahy] /ˈfoʊ saɪ, -kaɪ/ (Show IPA)
1.
a central point, as of attraction, attention, or activity:
The need to prevent a nuclear war became the focus of all diplomatic efforts.
2.
Physics. a point at which rays of light, heat, or other radiation, meet after being refracted or reflected.
3.
Optics.
  1. the focal point of a lens.
  2. the focal length of a lens.
  3. the clear and sharply defined condition of an image.
  4. the position of a viewed object or the adjustment of an optical device necessary to produce a clear image:
    in focus; out of focus.
4.
Geometry. (of a conic section) a point having the property that the distances from any point on a curve to it and to a fixed line have a constant ratio for all points on the curve.
5.
Geology. the point of origin of an earthquake.
6.
Pathology. the primary center from which a disease develops or in which it localizes.
verb (used with object), focused, focusing or (especially British) focussed, focussing.
7.
to bring to a focus or into focus:
to focus the lens of a camera.
8.
to concentrate:
to focus one's thoughts.
verb (used without object), focused, focusing or (especially British) focussed, focussing.
9.
to become focused.
Origin
1635-45; < Latin: fireplace, hearth
Related forms
focusable, adjective
focuser, noun
misfocus, verb, misfocused, misfocusing or (especially British) misfocussed, misfocussing.
misfocused, adjective
misfocussed, adjective
overfocus, verb (used with object), overfocused, overfocusing or (especially British) overfocussed, overfocussing.
refocus, verb, refocused, refocusing or (especially British) refocussed, refocussing.
self-focused, adjective
self-focusing, adjective
self-focussed, adjective
self-focussing, adjective
unfocusing, adjective
unfocussing, adjective
well-focused, adjective
well-focussed, adjective
Synonyms
1. center, heart, core, nucleus.
Examples from the web for focus
  • There's a time and place for everything and even children need to be able to focus and have an attention span.
  • He can focus his attention on something and hold it for a good spell.
  • The setup is designed to monitor the focus of attention in a fly's brain.
  • Bees either focus on gathering nectar or on gathering pollen depending on demand, especially in social species.
  • Upon him as a focus converge all rays of influence from the inclosing world.
  • The photographed blooms possess an unusual balance of both depth and focus, qualities often mutually exclusive.
  • They come back more well-centered, calm, able to focus on projects and work.
  • The media focus solely on poverty and the cycle of oppression.
  • He never had a chance to make friends, he said, or get settled or focus on his studies.
  • Even when sales were slow, she insisted that her husband turn down commercial illustration projects and focus on painting.
British Dictionary definitions for focus

focus

/ˈfəʊkəs/
noun (pl) -cuses, -ci (-saɪ; -kaɪ; -kiː)
1.
a point of convergence of light or other electromagnetic radiation, particles, sound waves, etc, or a point from which they appear to diverge
2.
another name for focal point (sense 1), focal length
3.
(optics) the state of an optical image when it is distinct and clearly defined or the state of an instrument producing this image: the picture is in focus, the telescope is out of focus
4.
a point upon which attention, activity, etc, is directed or concentrated
5.
(geometry) a fixed reference point on the concave side of a conic section, used when defining its eccentricity
6.
the point beneath the earth's surface at which an earthquake or underground nuclear explosion originates Compare epicentre
7.
(pathol) the main site of an infection or a localized region of diseased tissue
verb -cuses, -cusing, -cused, -cusses, -cussing, -cussed
8.
to bring or come to a focus or into focus
9.
(transitive) often foll by on. to fix attention (on); concentrate
Derived Forms
focusable, adjective
focuser, noun
Word Origin
C17: via New Latin from Latin: hearth, fireplace
Word Origin and History for focus
n.

1640s, from Latin focus "hearth, fireplace" (also, figuratively, "home, family"), of unknown origin, used in post-classical times for "fire" itself, taken by Kepler (1604) in a mathematical sense for "point of convergence," perhaps on analogy of the burning point of a lens (the purely optical sense of the word may have existed before Kepler, but it is not recorded). Introduced into English 1650s by Hobbes. Sense transfer to "center of activity or energy" is first recorded 1796.

v.

1775 in the literal sense; 1807 in the figurative sense, from focus (n.). Related: Focused; focusing; less commonly focussed; focussing.

focus in Medicine

focus fo·cus (fō'kəs)
n. pl. fo·cus·es or fo·ci (-sī', -kī')

  1. A point at which rays of light or other radiation converge or from which they appear to diverge, as after refraction or reflection in an optical system. Also called focal point.

  2. See focal length.

  3. The distinctness or clarity of an image rendered by an optical system.

  4. The state of maximum distinctness or clarity of such an image.

  5. An apparatus used to adjust the focal length of an optical system in order to make an image distinct or clear.

  6. The region of a localized bodily infection or disease.

v. fo·cused or fo·cussed, fo·cus·ing or fo·cus·sing, fo·cus·es or fo·cus·ses
  1. To cause light rays or other radiation to converge on or toward a central point; concentrate.

  2. To render an object or image in clear outline or sharp detail by adjustment of one's vision or an optical device.

  3. To adjust a lens or instrument to produce a clear image.

  4. To converge on or toward a central point of focus; be focused.

focus in Science
focus
  (fō'kəs)   
Plural focuses or foci (fō'sī', fō'kī')
  1. The degree of clarity with which an eye or optical instrument produces an image.

  2. See focal point.

  3. A central point or region, such as the point at which an earthquake starts.

  4. Mathematics A fixed point or one of a pair of fixed points used in generating a curve such as an ellipse, parabola, or hyperbola.

  5. The region of a localized bodily infection or disease.


focus in Technology
database, language
A hierarchical database language from Information Builders, Inc.
(1994-12-21)
Related Abbreviations for focus

FOCUS

Fisheries Oceanography Cooperative Users System