constant - a number representing a quantity assumed to have a fixed value in a specified mathematical context; "the velocity of light is a constant"

absorptance, absorption coefficient, coefficient of absorption - a measure of the rate of decrease in the intensity of electromagnetic radiation (as light) as it passes through a given substance; the fraction of incident radiant energy absorbed per unit mass or thickness of an absorber; "absorptance equals 1 minus transmittance"

coefficient of drag, drag coefficient - the ratio of the drag on a body moving through air to the product of the velocity and the surface area of the body

coefficient of friction - the ratio of the weight of an object being moved along a surface and the force that maintains contact between the object and the surface

coefficient of mutual induction, mutual inductance - a measure of the induction between two circuits; the ratio of the electromotive force in a circuit to the corresponding change of current in a neighboring circuit; usually measured in henries

coefficient of self induction, self-inductance - the ratio of the electromotive force produced in a circuit by self-induction to the rate of change of current producing it, expressed in henries

modulus - (physics) a coefficient that expresses how much of a specified property is possessed by a specified substance

coefficient of expansion, expansivity - the fractional change in length or area or volume per unit change in temperature at a given constant pressure

coefficient of reflection, reflectance, reflection factor, reflectivity - the fraction of radiant energy that is reflected from a surface

transmittance, transmission - the fraction of radiant energy that passes through a substance

absolute viscosity, coefficient of viscosity, dynamic viscosity - a measure of the resistance to flow of a fluid under an applied force

weighting, weight - (statistics) a coefficient assigned to elements of a frequency distribution in order to represent their relative importance