focus

fo·cus (f

n. pl. fo·cus·es or fo·ci (-s

, -k

)

a. 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: the focus of a lens. Also called focal point.

b. See focal length.

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

b. The state of maximum distinctness or clarity of such an image: in focus; out of focus.

c. An apparatus used to adjust the focal length of an optical system in order to make an image distinct or clear: a camera with automatic focus.

3. A center of interest or activity. See Synonyms at center.

4. Close or narrow attention; concentration: "He was forever taken aback by [New York's] pervasive atmosphere of purposefulness

the tight focus of its drivers, the brisk intensity of its pedestrians" Anne Tyler.

5. A condition in which something can be clearly apprehended or perceived: couldn't get the problem into focus.

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

7. Geology The point of origin of an earthquake.

8. Mathematics A fixed point whose relationship with a directrix determines a conic section.

v. fo·cused or fo·cussed, fo·cus·ing or fo·cus·sing, fo·cus·es or fo·cus·ses

v.tr.

1. To cause (light rays, for example) to converge on or toward a central point; concentrate.

a. To render (an object or image) in clear outline or sharp detail by adjustment of one's vision or an optical device; bring into focus.

b. To adjust (a lens, for example) to produce a clear image.

3. To direct toward a particular point or purpose: focused all their attention on finding a solution to the problem.

v.intr.

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

2. To adjust one's vision or an optical device so as to render a clear, distinct image.

3. To concentrate attention or energy: a campaign that focused on economic issues.

[Latin, hearth.]

focus·er n.

focus [foe-kuss, -sigh, -kye, -kee]

Verb

[-cusing, -cused] or -cussing, -cussed

1. to adjust one's eyes or an instrument on an object so that its image is clear

2. to concentrate

Noun

pl -cuses or -ci

1. a point of convergence of light or sound waves, or a point from which they appear to diverge

2. in focus (of an object or image being viewed) clear and sharp

3. out of focus (of an object or image being viewed) blurred and fuzzy

4. same as focal point or focal length

5. Optics the state of an optical image when it is distinct or the state of an instrument producing this image

6. a point upon which attention or activity is concentrated: the focus was on health and education

7. Geom a fixed reference point on the concave side of a conic section, used when defining its eccentricity [Latin: hearth, fireplace]

focus (f

Plural focuses or foci (f

, f

)

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.

ThesaurusLegend: Synonyms Related Words Antonyms

Noun	1.	focus - the concentration of attention or energy on something; "the focus of activity shifted to molecular biology"; "he had no direction in his life" centering, focusing, focussing, focal point, direction engrossment, immersion, absorption, concentration - complete attention; intense mental effort particularism - a focus on something particular
	2.	focus - maximum clarity or distinctness of an image rendered by an optical system; "in focus"; "out of focus" distinctness, sharpness - the quality of being sharp and clear
	3.	focus - maximum clarity or distinctness of an idea; "the controversy brought clearly into focus an important difference of opinion" clarity, clearness, limpidity, lucidity, lucidness, pellucidity - free from obscurity and easy to understand; the comprehensibility of clear expression
	4.	focus - a central point or locus of an infection in an organism; "the focus of infection" nidus, focal point point - the precise location of something; a spatially limited location; "she walked to a point where she could survey the whole street" focal infection - bacterial infection limited to a specific organ or region especially one causing symptoms elsewhere
	5.	focus - special emphasis attached to something; "the stress was more on accuracy than on speed" stress emphasis, accent - special importance or significance; "the red light gave the central figure increased emphasis"; "the room was decorated in shades of grey with distinctive red accents"
	6.	focus - a point of convergence of light (or other radiation) or a point from which it diverges focal point point - the precise location of something; a spatially limited location; "she walked to a point where she could survey the whole street"
	7.	focus - a fixed reference point on the concave side of a conic section point - the precise location of something; a spatially limited location; "she walked to a point where she could survey the whole street"
Verb	1.	focus - direct one's attention on something; "Please focus on your studies and not on your hobbies" pore, rivet, center, centre, concentrate engross, engulf, steep, soak up, immerse, absorb, plunge - devote (oneself) fully to; "He immersed himself into his studies" cerebrate, cogitate, think - use or exercise the mind or one's power of reason in order to make inferences, decisions, or arrive at a solution or judgments; "I've been thinking all day and getting nowhere" rivet - hold (someone's attention); "The discovery of the skull riveted the paleontologists" recall - cause one's (or someone else's) thoughts or attention to return from a reverie or digression; "She was recalled by a loud laugh" think - focus one's attention on a certain state; "Think big"; "think thin" zoom in - examine closely; focus one's attention on; "He zoomed in on the book" take heed, listen, hear - listen and pay attention; "Listen to your father"; "We must hear the expert before we make a decision"
	2.	focus - cause to converge on or toward a central point; "Focus the light on this image" refocus - focus once again; The physicist refocused the light beam" sharpen - make (images or sounds) sharp or sharper blur - to make less distinct or clear; "The haze blurs the hills"
	3.	focus - bring into focus or alignment; to converge or cause to converge; of ideas or emotions concenter, concentre, focalise, focalize align, aline, adjust, line up - place in a line or arrange so as to be parallel or straight; "align the car with the curb"; "align the sheets of paper on the table" refocus - focus anew; "The group needs to refocus its goals"
	4.	focus - become focussed or come into focus; "The light focused" focalise, focalize adapt, conform, adjust - adapt or conform oneself to new or different conditions; "We must adjust to the bad economic situation" slur, dim, blur - become vague or indistinct; "The distinction between the two theories blurred"
	5.	focus - put (an image) into focus; "Please focus the image; we cannot enjoy the movie" focalise, focalize, sharpen adjust, correct, set - alter or regulate so as to achieve accuracy or conform to a standard; "Adjust the clock, please"; "correct the alignment of the front wheels" refocus - put again into focus or focus more sharply; "refocus the image until it is very sharp" center, center on, concentrate on, focus on, revolve about, revolve around - center upon; "Her entire attention centered on her children"; "Our day revolved around our work" blear, blur - make dim or indistinct; "The fog blurs my vision"