(mathematics) Any function of a real variable whose value decreases as the variable increases.

(physics) The function governing the rate at which mechanical energy is converted to heat during viscous flow.

(psychology) The management of mental processes by the ego in order to meet an individual's needs

The transfer function of the forward path of a control system

The transfer function of the feedback path of a control system

An electronic device used to generate a signal representing the periodic value of a given mathematical function, especially sine, square, triangle and sawtooth waveforms

(physics) The relationship between the energy of an electron and its ability to excite an atom to a particular excited state

(mathematics) Any function that is a solution of the Bessel equation

(computing) Any character used to specify a function of a piece of software or hardware (such as carriage return of a printer)

(mathematics) Any function of a complex variable that is holomorphic throughout the complex plane