competence of the wind

In geology, the ability of the wind to transport solid particles either by rolling, by suspension, or by saltation (intermittent rolling and suspension).

It is usually expressed in terms of the weight of a single particle. This value varies with the wind speed and with the size, shape, and specific gravity of the particles.
Compare capacity of the wind.

An aggregation of sufficiently many atoms or molecules that it can be assigned macroscopic properties such as volume, density, pressure, and temperature.