vector

1 of 2

noun

vec·​tor ˈvek-tər 

plural vectors

1

a

: 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

2

a

: an organism (such as an insect) that transmits a pathogen from one organism or source to another

The insect vector in malaria is the anopheline mosquito, a genus comprising many species around the world.

—Frank Graham, Jr.

compare carrier sense 5a, reservoir sense 3

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

vector adjective

vectorial

vek-ˈtȯr-ē-əl 

adjective

vectorially

vek-ˈtȯr-ē-ə-lē 

adverb

vector

2 of 2

verb

vectored; vectoring ˈvek-t(ə-)riŋ 

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

Examples of vector in a Sentence

Noun

a mosquito that is the principal vector of yellow fever

Recent Examples on the Web

Noun

Robeson Jennings, senior VP of global services and intelligence at cybersecurity firm ZeroFox, told that the most successful attacks combine these multiple vectors. —Melissa Fleur Afshar, MSNBC Newsweek, 29 Oct. 2025

Now, Antarctica is the only location on Earth without the vector-carrying insect, according to the World Population Review. —Julia Jacobo, ABC News, 21 Oct. 2025

Verb

The fans also have individual flaps to vector the thrust. —Rohit Jaggi, Robb Report, 15 Aug. 2022

In 1998 an insect called the Asian Citrus Psyllid (ACP) showed up in Florida and caused concern because it was known to vector this disease while feeding on the tree’s sap. —Steven Savage, Forbes, 26 Jan. 2022

Word History

Etymology

Noun

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

First Known Use

Noun

1846, in the meaning defined at sense 1a

Verb

1941, in the meaning defined at sense 1

Phrases Containing vector

• characteristic vector
• intermediate vector boson
• radius vector
• vector field
• vector graphics
• vector product
• vector space
• vector sum
• vector vaccines
• zero vector

Rhymes for vector

• hector
• lector
• nectar
• rector
• sector
• specter
• spectre
• bisector
• collector
• connector
• corrector
• defector

Kids Definition

vector

noun

vec·​tor

ˈvek-tər

1

: a quantity that has magnitude and direction and that is usually represented by a line segment with the given direction and with a length representing the magnitude

2

: an organism (as an insect) that carries and passes on a disease-causing microbe

Medical Definition

vector

1 of 2 noun

vec·​tor ˈvek-tər 

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, reservoir sense 2

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

vectorial

vek-ˈtōr-ē-əl, -ˈtȯr- 

adjective

vector

2 of 2 transitive verb

vectored; vectoring -t(ə-)riŋ 

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

a disease vectored by flies