Hello, you have come here looking for the meaning of the word focus. In DICTIOUS you will not only get to know all the dictionary meanings for the word focus, but we will also tell you about its etymology, its characteristics and you will know how to say focus in singular and plural. Everything you need to know about the word focus you have here. The definition of the word focus will help you to be more precise and correct when speaking or writing your texts. Knowing the definition offocus, as well as those of other words, enriches your vocabulary and provides you with more and better linguistic resources.
Kepler introduced the term into mathematics and the sciences in describing elliptical orbits of planets (quote from Nicholas Mee) :
"One of the interesting properties of an ellipse is that if there were a light bulb at one focus, then all the light that it emits would reflect off the ellipse and converge at the other focus. This is why Kepler originally used the name focus for these points."[1]
Not long ago, it was difficult to produce photographs of tiny creatures with every part in focus.[…]A photo processing technique called focus stacking has changed that. Developed as a tool to electronically combine the sharpest bits of multiple digital images, focus stacking is a boon to biologists seeking full focus on a micron scale.
2004, Marian Singer, Trish MacGregor, The Only Wiccan Spell Book You'll Ever Need:
Candles, in fact, are an essential ingredient in many spells. They can be used as either the focus of the spell or as a component that sets the spell's overall mood and tone.
2014, Kristen S. Walker, Witch Gate, page 180:
I ran through what I knew about spells from Mom and other witchcraft sources, but nothing matched what I was used to seeing in her magic work. Usually she used herbs and other plants as a focus for the spell.
1961 February, “Talking of Trains: Collision at Newcastle”, in Trains Illustrated, pages 75–76:
The difficulties of focussing colour-light signals on curved tracks to ensure maximum sighting distance were underlined in the recent official report [...] on a low-speed collision at Newcastle Central on July 25, 1960, between an unfitted freight and a diesel-hauled passenger train.
You'll need to focus the microscope carefully in order to capture the full detail of this surface.
(intransitive,optics, of a lens, optical instrument, etc.) To adjust itself or be adjusted such that light from a scene converges appropriately to create a clear image.
I can't get the lens to focus.
The camera focuses automatically on the subject's eyes.
(transitive) To direct attention, effort, or energy to a particular audience or task.
The president focused her remarks on the newcomers.
1897, Bram Stoker, Dracula, published 1993, page 67:
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.
Usage notes
The spellings with -ss- are more common in Commonwealth English than in American English, but in both varieties they are less common than the spellings focuses, focusing, focused.
^ Philippa, Marlies, Debrabandere, Frans, Quak, Arend, Schoonheim, Tanneke, van der Sijs, Nicoline (2003–2009) Etymologisch woordenboek van het Nederlands (in Dutch), Amsterdam: Amsterdam University Press
Matasović, and Hamp before him, opt to derive this from Proto-Indo-European*dʰegʷʰ-(“to burn”); Matasović believes that the -c- would have spread from the nominative of a root noun *dʰṓgʷʰ-s (> *dʰṓkʷʰ-s).[1]
^ Matasović, Ranko (2010) “The etymology of Latin focus and the devoicing of final stops before *s in Proto-Indo-European”, in Historische Sprachforschung / Historical Linguistics, volume 123, Vandenhoeck & Ruprecht, →ISSN, →JSTOR, pages 212–216
Further reading
“focus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
“focus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
focus in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
focus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
Carl Meißner, Henry William Auden (1894) Latin Phrase-Book, London: Macmillan and Co.
to fight for hearth and home: pro ariset focis pugnare, certare, dimicare
“focus”, in Harry Thurston Peck, editor (1898), Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers
“focus”, in William Smith et al., editor (1890), A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin
De Vaan, Michiel (2008) Etymological Dictionary of Latin and the other Italic Languages (Leiden Indo-European Etymological Dictionary Series; 7), Leiden, Boston: Brill, →ISBN, pages 228-9