Z stands for it in electronics

• Measured in ohms
• A material's opposition to the flow of electric current
• Characteristic of a current politician that is entertaining with moves

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Impedance \Im*ped"ance\, n. [Impede + -ance.] (Elec.) The apparent resistance in an electric circuit to the flow of an alternating current, analogous to the actual electrical resistance to a direct current, being the ratio of electromotive force to the ...

Wiktionary Word definitions in Wiktionary
n. 1 (label en physics) 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. 2 (label en ...

Longman Dictionary of Contemporary English Word definitions in Longman Dictionary of Contemporary English
noun COLLOCATIONS FROM CORPUS ■ ADJECTIVE high ▪ This provides a relatively high input impedance looking into their bases and a low output impedance at the emitters. ▪ Its high input impedance means that it does not load a signal source which it copies ...

Wikipedia Word definitions in Wikipedia
Impedance is the complex-valued generalization of resistance . It may refer to: Acoustic impedance , a constant related to the propagation of sound waves in an acoustic medium Electrical impedance , the ratio of the voltage phasor to the electric current ...

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1886, from impede + -ance .