(mathematics) The factorization of a positive integer into its constituent prime numbers

An antigen of the Rhesus system; understood unless otherwise specified to refer to Rhesus factor D (RhD), which appears on the surface of the red blood cells of most (85%) humans. An incompatibility between the Rh-blood types of a mother and her baby may cause serious disease for the baby.

(idiomatic) An unknown or hard-to-define influence; a factor with unknown or unforeseeable consequences. / (idiomatic) A special talent, ability or quality or its indefinable cause.

Alternative spelling of X factor

Alternative spelling of X factor

Alternative spelling of X factor

(mathematics) The decomposition of a composite number into a product of smaller integers

(economics) A resource used to produce goods and services, such as labor, land, or capital.

(slang, Britain) Sod's law or Murphy's law: "Anything that can go wrong will go wrong."

plural of factor space