# Parameter definition

pə-rămĭ-tər
Frequency:
Any constant, with variable values, used as a referent for determining other variables.
noun
(math.) A quantity or constant whose value varies with the circumstances of its application, as the radius line of a group of concentric circles, which varies with the circle under consideration.
noun
The definition of a paramater is a guideline, boundary or outer limit.

An example of parameter is a guideline in which an experiment is to take place.

noun
(geometry) In the ellipse and hyperbola, a third proportional to any diameter and its conjugate, or in the parabola, to any abscissa and the corresponding ordinate.

The parameter of the principal axis of a conic section is called the latus rectum.

noun
(usage problem) A factor that restricts what is possible or what results.
noun
A factor that determines a range of variations; a boundary.

An experimental school that keeps expanding the parameters of its curriculum.

noun
A boundary or limit.
noun
(statistics) A quantity, such as a mean, that is calculated from data and describes a population.
noun
(programming) A name in a function or subroutine definition that is replaced by, or bound to, the corresponding actual argument when the function or subroutine is called: a formal parameter.

Roughly, a tuple of arguments could be thought of as a vector, whereas a tuple of parameters could be thought of as a covector (i.e., linear functional). When a function is called, a parameter tuple becomes "bound" to an argument tuple, allowing the function instance itself to be computed to yield a return value. This would be roughly analogous to applying a covector to a vector (by taking their dot product (or, rather, matrix-product of row vector and column vect)) to obtain a scalar.

noun
(programming) The value which is passed into the function to instantiate such a name; the argument or actual parameter.
noun
(crystallography) The ratio of the three crystallographic axes which determines the position of any plane.
noun
(crystallography) The fundamental axial ratio for a given species.
noun
A characteristic or feature that distinguishes something from others.
noun
(usage problem) A distinguishing characteristic or feature.
noun
A constant in an equation that varies in other equations of the same general form, especially such a constant in the equation of a curve or surface that can be varied to represent a family of curves or surfaces.
noun
One of a set of independent variables that express the coordinates of a point.
noun
A factor or characteristic.
noun
(mathematics, physics) A variable kept constant during an experiment, calculation or similar.
noun
One of a set of measurable factors, such as temperature and pressure, that define a system and determine its behavior and are varied in an experiment.
noun

## Alternative Forms

Alternative Form of parameter - parametre

Singular:
parameter
Plural:
parameters

## Origin of parameter

• New Latin parametrum a line through the focus and parallel to the directrix of a conic Greek para- beside para–1 Greek metron measure –meter

### From American Heritage Dictionary of the English Language, 5th Edition

• From French paramètre, from New Latin parametrum (“parameter"), from Ancient Greek παρά (para, “beside") + μέτρον (metron, “measure").