vec·​tor | \ˈvek-tər \

Definition of vector 

(Entry 1 of 2)

1a : a quantity that has magnitude and direction and that is commonly represented by a directed line segment whose length represents the magnitude and whose orientation in space represents the direction broadly : an element of a vector space

b : a course or compass direction especially of an airplane

2a : an organism (such as an insect) that transmits a pathogen

b : pollinator sense a

3 : an agent (such as a plasmid or virus) that contains or carries modified genetic material (such as recombinant DNA) and can be used to introduce exogenous genes into the genome of an organism


vectored; vectoring\ ˈvek-​t(ə-​)riŋ \

Definition of vector (Entry 2 of 2)

transitive verb

1 : to guide (something or someone, such as an airplane, its pilot, or a missile) in flight by means of a radioed vector

2 : to change the direction of (the thrust of a jet engine) for steering

Keep scrolling for more

Other Words from vector


vector adjective
vectorial \ vek-​ˈtȯr-​ē-​əl \ adjective
vectorially \ vek-​ˈtȯr-​ē-​ə-​lē \ adverb

Examples of vector in a Sentence


a mosquito that is the principal vector of yellow fever

Recent Examples on the Web: Noun

Climate change is expanding the reach of disease-bearing vectors like mosquitoes into new regions and putting new populations at risk. Ron Klain, Vox, "A pandemic killing tens of millions of people is a real possibility — and we are not prepared for it," 15 Oct. 2018 The best known vectors for these DDoS amplification attacks are poorly secured domain name system resolution servers, which magnify volumes by as much as 50 fold, and network time protocol, which increases volumes by about 58 times. Dan Goodin, Ars Technica, "In-the-wild DDoSes use new way to achieve unthinkable sizes," 27 Feb. 2018 The former physics major — who uses single-length irons, relies on vector putting and implements a single-plane swing — has made plenty of noise with his unorthodox methods. Dargan Southard, USA TODAY, "Bryson DeChambeau says compass was never meant to 'skirt the rules'," 11 July 2018 Dogs and other carnivores are the definitive hosts, and mosquitoes serve as vectors. Marci Robin, Allure, "Woman Discovers the Moving Bump Below Her Skin Is Actually a Parasitic Worm," 22 June 2018 So, lots of research looking for good, better, and best vectors—which will likely differ depending on the target and the disease. Sharon Begley, STAT, "Archived chat: last week in CRISPR — cancer, patents, and a dip in the market," 19 June 2018 Participants will learn how to create vector illustrations and logos, among other basic tasks. Margeaux Sippell,, "Business agenda," 14 June 2018 For optimal cornering, the all-wheel-drive system has the ability to vector torque to the wheel that needs it. Tom Voelk, New York Times, "Porsche Mission E Cross Turismo Review: ‘Silence Is the New Power’," 6 June 2018 But the Hamers’ work is the first to deploy the technology to track insect vectors of disease. Katherine J. Wu, Smithsonian, "How Tiny Trackers Could Help Humans Avoid Kissing Bugs’ Deadly Smooch," 9 July 2018

Recent Examples on the Web: Verb

Torque vectoring all-wheel drive is a $2,200 option with either engine. Dan Neil, WSJ, "2018 Kia Stinger GT2: The Best German Car to Come Out of South Korea," 6 Apr. 2018 Powertrains are unchanged from current Quadrifoglio spec, meaning that both vehicles carry the 505-hp twin-turbocharged 2.9-liter V-6 engine, eight-speed ZF transmission, and Alfa’s torque-vectoring differential and Chassis Domain Control system. Andrew Wendler, Car and Driver, "NRING the Dragon: Nurburgring Edition Alfa Romeo Quadrifoglios Revealed," 5 Mar. 2018 View 24 Photos Honda-philes will be thrilled to learn the 2019 RDX marks the return of torque-vectoring all-wheel drive to the RDX. Andrew Wendler, Car and Driver, "2019 Acura RDX Crossover: Return of the Turbocharged Four," 29 Mar. 2018 The QF’s handling is also aided by a torque-vectoring rear differential that can send 100 percent of the torque to either rear wheel, as traction and driving modes dictate. Rich Ceppos, Car and Driver, "2018 Alfa Romeo Stelvio Quadrifoglio," 3 Mar. 2018 The Super Hornets conferred with the USS Princeton and were vectored to a CAP point 60 miles away. Kyle Mizokami, Popular Mechanics, "That Time the U.S. Navy Had a Close Encounter With a UFO," 18 Dec. 2017 Those rear motors can rotate at different speeds to afford the e-Evo torque vectoring across its aft axle. Alexander Stoklosa, Car and Driver, "Mitsubishi e-Evolution Concept Eclipses Another Great Name," 25 Oct. 2017 Ride, Handling, and Steering With a standard Drift mode that uncorks the torque-vectoring rear axle for greater agility in corners, the Focus RS can play along with your inner Ken Block. Car and Driver, "2018 Ford Focus RS," 26 Oct. 2017 On a recent flight from San Francisco to Honolulu my plane swung west over the southern tip of the Big Island before vectoring north toward Oahu. Austin Murphy,, "It's an Island Ting: Kahuku High in Oahu Churns Out NFL Studs Like Schools in Florida and Texas," 25 Oct. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'vector.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of vector


1846, in the meaning defined at sense 1a


1941, in the meaning defined at sense 1

History and Etymology for vector


earlier, short for radius vector, borrowed from Latin, "carrier, conveyer," from vec-, alternate stem of vehere "to convey, carry" + -tor, agent suffix — more at way entry 1

Keep scrolling for more

Learn More about vector

Statistics for vector

Last Updated

15 Nov 2018

Look-up Popularity

Time Traveler for vector

The first known use of vector was in 1846

See more words from the same year

Keep scrolling for more

More Definitions for vector



English Language Learners Definition of vector

mathematics : a quantity (such as velocity) that has size and direction

: the course or direction of an airplane

biology : an insect, animal, etc., that carries germs that cause disease


vec·​tor | \ˈvek-tər \

Kids Definition of vector

: a living thing (as a mosquito, fly, or tick) that carries and passes on a disease-causing microorganism


vec·​tor | \ˈvek-tər \

Medical Definition of vector 

(Entry 1 of 2)

1 : a quantity that has magnitude and direction and that is usually represented by part of a straight line with the given direction and with a length representing the magnitude

2 : an organism (as an insect) that transmits a pathogen from one organism or source to another fleas are vectors of plague — compare carrier sense 1a

3 : an agent (as a plasmid or virus) that contains or carries modified genetic material (as recombinant DNA) and can be used to introduce exogenous genes into the genome of an organism

Other Words from vector

vectorial \ vek-​ˈtōr-​ē-​əl, -​ˈtȯr-​ \ adjective
vectored; vectoring\ -​t(ə-​)riŋ \

Medical Definition of vector (Entry 2 of 2)

: to transmit (a pathogen or disease) from one organism to another : act as a vector for a disease vectored by flies

Keep scrolling for more

Comments on vector

What made you want to look up vector? Please tell us where you read or heard it (including the quote, if possible).


full of whispering sounds

Get Word of the Day daily email!

Test Your Vocabulary

Difficult Vocab Quiz

  • the-education-of-achilles-eugne-delacroix
  • Which is a synonym of discomfit?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

Add Diction

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!