The measurement of a specific substance's ability to absorb radiant energy; absorptivity.

(marine chemistry) A measure of how readily ocean waters will uptake atmospheric carbon dioxide.

(quantum mechanics) A normalized complex number, considered as, say, the scalar coefficient of a ket.

(economics) The system or infrastructure for economic exchange within which factors of production (such as labor, materials, or capital) are purchased or sold.

(category theory) Said of a morphism: to be equal to a composition of two morphisms, one of which is the given morphism (that is being said to be "factored through").

(uncountable, statistics) A statistical method used to describe variability among observed correlated variables in terms of one or more unobserved variables (called factors).

(military, slang) The level of stress and/or adrenaline in a dangerous situation.

plural of factor analysis

(colloquial, humorous) The degree to which somebody cares about something.

(US, slang) An intangible quality, usually attributed to certain items of professional equipment but sometimes to particular positions within predominantly and traditionally male professions such as law enforcement and the military where the term is most frequently used, that is believed to stir inordinate interest in obtaining the item or position because it makes the possessor feel confident, cool and thus desirable to women.