(biochemistry) Any of various substances that cause apoptosis in cells

The lure of another home, country, region, organization, or religion.

(physics) The ratio of the RMS value to the absolute mean of a sinusoidal wave (especially to that of an alternating current)

plural of form factor

(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

plural of X factor