mobility (general) 

https://doi.org/10.1351/goldbook.MT06760
Mass transport is described by a mobility b, defined by: bi=νiFi where νi is the average drift velocity and Fi is the force on particle i.
Source:
PAC, 1999, 71, 1307. (Definitions of Terms for Diffusion in the Solid State) on page 1319 [Terms] [Paper]