impedance

noun

im·​ped·​ance im-ˈpē-dᵊn(t)s 

: something that impedes : hindrance: such as

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 ratio of the pressure to the volume displacement at a given surface in a sound-transmitting medium

Examples of impedance in a Sentence

Recent Examples on the Web

The impedance scarcely varies from a nominal 6Ω over most of the frequency range. —Mark Sparrow, Forbes, 1 Nov. 2024

Maybe the game won't sync across platforms, and the impedance of having to start all over will be enough to prevent notable devolution. —Kevin Purdy, Ars Technica, 5 Sep. 2024

Its frequency range is stated as an impressive 13 Hz to 35 kHz, and a nominal impedance of 8 ohms, dipping to 3 ohms. —Robert Ross, Robb Report, 10 July 2024

Bioelectrical impedance analysis, which uses electric signals to tell fat from muscle in the body, is becoming more common in medical offices. —Lydia Denworth, Scientific American, 1 Jan. 2024

Word History

First Known Use

1886, in the meaning defined above

Medical Definition

impedance

noun

im·​ped·​ance im-ˈpēd-ᵊn(t)s 

1

: 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

2

: the ratio of the pressure to the volume displacement at a given surface in a sound-transmitting medium

3

: opposition to blood flow in the circulatory system