variable quantity, variable - a quantity that can assume any of a set of values

cross product, vector product - a vector that is the product of two other vectors

vector sum, resultant - a vector that is the sum of two or more other vectors

radius vector - a line connecting a point in space to the origin of a polar coordinate system

radius vector - a line connecting a satellite to the center of the body around which it is rotating

straight line - a line traced by a point traveling in a constant direction; a line of zero curvature; "the shortest distance between two points is a straight line"

ray - (mathematics) a straight line extending from a point

animal, animate being, beast, creature, fauna, brute - a living organism characterized by voluntary movement

microorganism - any organism of microscopic size

agent - an active and efficient cause; capable of producing a certain effect; "their research uncovered new disease agents"

gene delivery vector, transducing vector - a vector for delivering genes into cells

immune carrier, carrier - a person who has some pathogen to which he is immune but who can pass it on to others