noun
vector
A quantity with direction and magnitude, or an organism or agent that carries disease.
Where it comes from
Vector ordinarily means a quantity with direction and magnitude, or an organism or agent that carries disease. Vector was borrowed from Latin vector, a carrier or conveyer. The noun was formed from the stem of vehere, to carry or convey, plus the agent suffix -tor, so it literally named something or someone that carries. Astronomers used vector in radius vector for a line imagined as carrying a moving planet around a center. Mathematics generalized it into a directed quantity.
How the meaning developed
Medicine and biology later returned to the plain carrier idea for organisms or agents that convey disease or genetic material.
Sources
- Vector Definition & Meaning
- Earliest Known Uses of Some of the Words of Mathematics (V)
- Vector: Etymology, Origin & Meaning
Definitions adapted from Open English WordNet where applicable. License and attribution. Word-history text comes from Lexifour’s sourced social research; pages are assembled automatically, not individually fact-checked on every update.
Updated 2026-10-05. Report a correction.