(mathematics, complex analysis, algebraic geometry) Any function expressible as the quotient of two (coprime) polynomials (and which thus has poles at a finite, discrete set of points which are the roots of the denominator).

(physics) A function which describes the intensity of scattered radiation in any given direction

(computing) A function used in an operating system that is not available to application programs.

(mathematics) Any function whose range is n-dimensional

plural of fuller

The ratio of the mass of fuel used to the output power of an engine (used especially of aircraft engines)

An undertaker; one who arranges funerals.

(idiomatic, vulgar, followed by a wh-clause) I don't know; nobody knows; it is unclear.

(idiomatic) To make a complete change or reform. / (idiomatic) To complete a cycle of transition, returning to where one started after gaining experience or exploring other things.

(US) A mortuary or funeral home.