permeance

/P ER1 M IY0 AH0 N S/
noun
  1. 1

    A measure of the degree to which a material allows a fluid to permeate it.

  2. 2

    The reciprocal of reluctance in a magnetic circuit; the analogue of conductance in an electrical circuit.

Source: https://en.wiktionary.org/wiki/permeance