vector

Noun

• (genetics) a virus or other agent that is used to deliver DNA to a cell

• any agent (person or animal or microorganism) that carries and transmits a disease
  • mosquitos are vectors of malaria and yellow fever
    
  • fleas are vectors of the plague
    
  • aphids are transmitters of plant diseases
    
  • when medical scientists talk about vectors they are usually talking about insects
    

• a straight line segment whose length is magnitude and whose orientation in space is direction

• a variable quantity that can be resolved into components