flaukse fu'ivla

x1 is the vector flux (flow) of quantity/substance (count) x2 through (geometric/imaginary) hypersurface/embedded manifold x3 per unit hyperarea per unit time.

This is the transport phenomena sense of "flux": a density of flow, the maximal rate of flow of a subsramce or quantity (x2) through a differential hypersurface. If the hypersurface x3 is n-dimensional spatially and the dimensionality (units) of x2 is U, then the dimensionality (units) of x1 is U/(1 mn * s). Fairly similar to nildenmi. For the hypersurface integral of this quantity (with respect to the normal), use: flaumji. See also: flecu.

In notes:

x1 is the scalar flux (total flow) of quantity/substance x2 through bounding Jordan orientable manifold x3 under conditions and conventions of definition x4 (including actual orientation of x3, signum of outflux, etc.)