Polydisperse

A collection of objects is called polydisperse or polysized if they have a broad range of size, shape and mass characteristics. A sample of objects that have a uniform size, shape and mass distribution are called monodisperse. In practice, polydisperse collections are common because it is relatively easy to create a polydisperse collection of particles, objects or polymers. Monodisperse collections, on the other hand, are extremely uncommon because the technological challenges that must be overcome in order to produce such collections are often enormous.

Examples:

Polymers: Most will possess a distribution of molecular mass

Particles: Most manufactured particles will possess a wide distribution of size, surface area and mass

Thin-films: Most thin-films will possess a varied distribution of film thickness.