• X-ray focus tube
    X-ray focus tube
  • WordNet 3.6
    • v focus put (an image) into focus; we cannot enjoy the movie" "Please focus the image"
    • v focus become focussed or come into focus "The light focused"
    • v focus direct one's attention on something "Please focus on your studies and not on your hobbies"
    • v focus bring into focus or alignment; to converge or cause to converge; of ideas or emotions
    • v focus cause to converge on or toward a central point "Focus the light on this image"
    • n focus maximum clarity or distinctness of an image rendered by an optical system "in focus","out of focus"
    • n focus maximum clarity or distinctness of an idea "the controversy brought clearly into focus an important difference of opinion"
    • n focus the concentration of attention or energy on something "the focus of activity shifted to molecular biology","he had no direction in his life"
    • n focus a fixed reference point on the concave side of a conic section
    • n focus a point of convergence of light (or other radiation) or a point from which it diverges
    • n focus a central point or locus of an infection in an organism "the focus of infection"
    • n focus special emphasis attached to something "the stress was more on accuracy than on speed"
    • ***
Webster's Revised Unabridged Dictionary
  • Interesting fact: Methylphenidate (Ritalin) is a medication prescribed for individuals (usually children) who have an abnormally high level of activity or attention-deficit hyperactivity disorder (ADHD). According to the National Institute of Mental Health, about 3 to 5 percent of the general population has the disorder, which is characterized by agitated behavior and an inability to focus on tasks. Methylphenidate also is occasionally prescribed for treating narcolepsy. Methylphenidate is a central nervous system (CNS) stimulant. It has effects similar to, but more potent than, caffeine and less potent than amphetamines. It has a notably calming effect on hyperactive children and a "focusing" effect on those with ADHD.
    • Focus A central point; a point of concentration.
    • Focus (Opt) A point in which the rays of light meet, after being reflected or refracted, and at which the image is formed; as, the focus of a lens or mirror.
    • Focus (Geom) A point so related to a conic section and certain straight line called the directrix that the ratio of the distance between any point of the curve and the focus to the distance of the same point from the directrix is constant.
    • v. t Focus To bring to a focus; to focalize; as, to focus a camera.
    • ***
Century Dictionary and Cyclopedia
  • Interesting fact: Whales can never focus both their eyes on the same object at once
    • n focus In optics, a point at which rays of light that originally diverged from one point meet again, or a point from which they appear to proceed. The former is called a real, the latter a virtual focus. The principal focus of a lens is the focus of rays striking the lens parallel to its axis. The conjugate foci of a mirror or lens are two points so situated that the rays emitted from a luminous body at either point are reflected (by the mirror) or refracted (by the lens) to the other. See conjugate mirror (under conjugate), lens, and mirror.
    • n focus In geometry, a point from which the distances to any point of a given curve are in a syzygetic relation. Thus, the sum of the distances of any point of an ellipse from its foci is constant, and the difference of the distances of any point of a hyperbola from its foci is constant. A modern definition is that the foci are the intersections of common tangents of the curve and the absolute. In like manner, a focus of a surface is a point on the curve of intersection of common tangent planes of the surface and the absolute. See cuts under Cartesian and ellipse.
    • n focus In the theory of perspective, with reference to two planes in perspective, one of four points—two, F1 and F2, on one plane, and two, f1 and f2, on the other—such that the angles between two points on the first plane measured at F1 are equal to the angles between the corresponding points on the other plane measured at f1, and so with the pair of foci F2 and f2. One pair of foci are called similar, because the angles are measured in the same direction on the two planes; the other pair are called dissimilar, because the angles are measured in opposite directions.
    • n focus Figuratively (with a consciousness of the classical Latin meaning), a central or gathering point, like the fire or hearth of a household; the point at or about which anything is concentrated; a center of interest or attraction.
    • focus To bring or adjust to a focus; cause to be in focus; focalize; collect in one point; concentrate.
    • n focus In pathology, a center of morbid action; one of the primary or principal lesions.
    • ***
Chambers's Twentieth Century Dictionary
  • Interesting fact: Focus group information compiled by CalComp revealed that 50 percent of computer users do not like using a mouse.
    • n Focus fō′kus (opt.) a point in which several rays meet and are collected after being reflected or refracted, while a virtual focus is a point from which rays tend after reflection or refraction—the principal focus is the focus of parallel rays after reflection or refraction: any central point
    • v.t Focus to bring to a focus: to concentrate:—pa.p. fō′cussed
    • ***


  • Norman Vincent Peale
    “When every physical and mental resources is focused, one's power to solve a problem multiplies tremendously.”
  • Steffi Graf
    Steffi Graf
    “As long as I can focus on enjoying what I'm doing, having fun, I know I'll play well.”
  • Les Brown
    “You must remain focused on your journey to greatness.”
  • Jack Dixon
    Jack Dixon
    “If you focus on results, you will never change. If you focus on change, you will get results.”
  • Kent Steffes
    Kent Steffes
    “To succeed at the level I want to you have to be focused and serious.”
  • Source Unknown
    Source Unknown
    “The first rule of focus is Wherever you are be there.”


Webster's Revised Unabridged Dictionary
L. focus, hearth, fireplace; perh. akin to E. bake,. Cf. Curfew Fuel Fusil the firearm


In literature:

But she was hopelessly out of focus by this time, and it was weary work getting her in.
"Lotus Buds" by Amy Carmichael
He squinted hard to get the newspaper into proper focus.
"The Night Riders" by Ridgwell Cullum
If the micrometer is not properly in focus after a few trials, it may easily be made right.
"The Story of the Cotton Plant" by Frederick Wilkinson
She stared straight ahead of her, focusing some trifling detail of the pattern on the wall paper.
"The Golden Woman" by Ridgwell Cullum
The fine strength of powerful bodies will not allow the mind to focus such things.
"The Twins of Suffering Creek" by Ridgwell Cullum
He could not bring himself into mental focus.
"Astounding Stories of Super-Science, June, 1930" by Various
From the lens of the focusing machine shot a pale, amber beam.
"Astounding Stories of Super-Science, October, 1930" by Various
The far-reaching plains to the west offered him too wide a focus.
"The Law-Breakers" by Ridgwell Cullum
Then he glanced over, and his mild eyes focused themselves on the bottle protruding from Jim's pocket.
"The One-Way Trail" by Ridgwell Cullum
Sometimes one figure would come into sharp focus for a fraction of a second, sometimes in color, sometimes not.
"The Foreign Hand Tie" by Gordon Randall Garrett

In poetry:

In whom eternally
Thou, Light, dost focus Thee!--
Didst pave
The way o' the wave;
"Any Saint" by Francis Thompson
In prudence, now, we break the glass;
We must view churches but in mass.
Nor split too nicely at the focus
Opinions, jumbled hocus-pocus.
"Experimentum Crucis" by John Kenyon
Living, time passing, it is preferable
to focus the memory in turn upon
the more distant retrospects in order
that the present mind may retain its peace.
"Living" by Ben Jonson
There were trains that went in the tunnels
and never came out. The eyes of horses
focused and trotted to their deaths.
The corn slept in the cistern
and was rotted when it woke.
"Cipriana" by Ernesto Trejo
So, blest was Columbia; the focus of Nature's
Best gifts, and the dimple where rested God's smile;
The Queen of the World in her young strength and beauty,
The pride of the skies in her freedom from guile.
"Pro Patria: America, 1861" by Adah Isaacs Menken
Walking, snow falling, it is possible
to focus at various distances
in turn on separate flakes, sharply engage
the attention at several spatial points:
the nearer cold and more uncomfortable,
the farther distanced and almost pleasing.
"Living" by Ben Jonson

In news:

"Focus is something we have really been working on," Sexton said.
The endorsement was poorly written and heavily focused on negative press.
Going into the turn, I try focus on positioning on my board.
Hopefully the attempt to regulate Uber will focus on the fracas's real victims: people who find both sides despicable.
Another Bedlam beckons, calling for acute focus and analysis on the matchups.
Dave's joins smashburger, Red Robin and others in town all with one focus.
Kittur, who was born in Mumbai, India, and has lived in St Louis for three years, focuses primarily on Indian cuisine, though curiosity might be her true driving force.
Review focuses on just one side of balance sheet .
Portrait of a young man on green blurry background - shallow DOF, focus on eyes.
They May Ballyhoo , We'll Stay Focused on Black Women.
She appeals for calm and says the focus should be on the president's funeral.
Focusing on the Promise of Affordable Solar Power in India.
Banish galloping insecurity and focus on what's real.
Alicia Bassuk says tension between workers with kids and workers without could be avoided by focusing on contribution, not face time.
WWE has changed its focus, watched its prices and broadened programming to stay on top.

In science:

We fix a point P and focus on the ball of radius 1/√N about P .
Universality and scaling of zeros on symplectic manifolds
This subsection will focus on the finite unitary groups, with remarks about symplectic and orthogonal groups at the end.
Random matrix theory over finite fields: a survey
In this paper, I focus on the following de(cid:12)nition, which does result in an acceptable cps.
Conditional Plausibility Measures and Bayesian Networks
Although my focus here is independence, irrelevance is an interesting notion in its own right; see (Cozman,  ; Cozman & Walley,  ). .
Conditional Plausibility Measures and Bayesian Networks
Similarly, I have focused only on acceptable cps's, that is, ones that satisfy Acc{.
Conditional Plausibility Measures and Bayesian Networks