impedance

noun5

1. •
   The act of impeding; that which impedes; a hindrance.
2. •
   A measure of the opposition to the flow of an alternating current in a circuit; the aggregation of its resistance, and inductive and capacitive reactances; the ratio of voltage to current treated as complex quantities.
3. •
   A quantity analogous to electrical impedance in some other energy domain
4. •
   a measure of opposition to motion of something subjected to a force; the ratio of force to velocity treated as complex quantities.
5. •
   the ratio of sound pressure to volume flow rate treated as complex quantities.