Comment by antonvs

> A bell-curve is the amortised function of a random variable with a mean and standard deviation.

The general notion of a bell-shaped curve is broader than that. Wikipedia has a reasonable overview: https://en.wikipedia.org/wiki/Bell-shaped_function

> “typically continuous or smooth, asymptotically approach zero for large negative/positive x, and have a single, unimodal maximum at small x.”