ə̇mˈpēd ə n(t)s noun
( -s )
Etymology: impede + -ance
1.
a. : the apparent opposition in an electrical circuit to the flow of an alternating current that is analogous to the actual electrical resistance to a direct current and that is the ratio of effective electromotive force to the effective current
b. : the resistance to passage of a substance (as water or water vapor) through a film
2. : the ratio of the pressure to the volume displacement at a given surface in a sound-transmitting medium