Yeah, a measurement of the speed of a lot of molecules.

Temperature is a statistical property of a macroscopic system that reduces a large number of variables of a microscopic system to a single scalar value.

It doesn't explain so much as summarize and it does so about as well as a mean or a median (which makes sense because temperature is literally the average of all the kinetic energies of all the microscopic components). It doesn't tell you about the distribution of energies, although in some extremely simple model systems you can compute the distribution: https://en.wikipedia.org/wiki/Maxwell%E2%80%93Boltzmann_dist...