(cosmology) the ratio of the speed of recession of a galaxy (due to the expansion of the universe) to its distance from the observer; the Hubble constant is not actually a constant, but is regarded as measuring the expansion rate today

a constant in the equation of a curve that can be varied to yield a family of similar curves

any factor that defines a system and determines (or limits) its performance

(computer science) a reference or value that is passed to a function, procedure, subroutine, command, or program

a quantity (such as the mean or variance) that characterizes a statistical population and that can be estimated by calculations from sample data