D defs.my
Entry 2 senses Webster, 1913

Vector

/vĕk'tər/ · Vec·tor · IPA /ˈvɛktɚ/
01 n. Same as Radius vector.
  1. 1.
    Same as Radius vector. See: Radius vector
  2. 2.
    A directed quantity, as a straight line, a force, or a velocity. Vectors are said to be equal when their directions are the same and their magnitudes equal. Cf. Scalar.(Math.) See: Scalar