Argument (Function)

An argument of a Function $f(x_1, \ldots, x_n)$ is one of the $n$ parameters on which the function's value depends. For example, the Sine $\sin x$ is a one-argument function, the Binomial Coefficient ${n\choose m}$ is a two-argument function, and the Hypergeometric Function ${}_2F_1(a,b;c;z)$ is a four-argument function.