"Energy Density of States" refers to electrons or other entities, e.g. phonons. It quantifies the numnber of states in an infitesimal energy range, per volume, and has dimensionality of inverse energy times inverse volume.
$\rho(E) = n_E(E) = \frac{dN(E)}{dE}\frac{1}{V}$, where $N(E)$ is the total number of states with energy less than $E$, and $V$ is the volume.
Applicable units are those of quantitykind:EnergyDensityOfStates
Energy Density of States