a quantity that can assume any of a set of values | (genetics) a virus or other agent that is used to deliver DNA to a cell |
a symbol (like x or y) that is used in mathematical or logical expressions to represent a variable quantity | a variable quantity that can be resolved into components |
something that is likely to vary; something that is subject to variation | any agent (person or animal or microorganism) that carries and transmits a disease |
a star that varies noticeably in brightness | a straight line segment whose length is magnitude and whose orientation in space is direction |