This week’s Word of the Week is, “Factor.” noun one of the elements contributing to a particular result or situation: Poverty is only one of the factors in crime. Mathematics. one of two or more numbers, algebraic expressions, or the like, that when multiplied together produce a given product; a divisor: 6 and 3 are factors of 18. Biochemistry. any of certain substances necessary to a biochemical or physiological process, especially those whose exact nature and function are unknown. verb (used with object) Mathematics. to express (a mathematical quantity) as a product of two or more quantities of like kind, as 30 = 2·3·5, or x2− y 2= ( x + y) ( x − y). to act as a factor for. verb phrases factor in/into, to include as an essential element, especially in forecasting or planning: You must factor insurance payments into the cost of maintaining a car.