# hertz

/ˈhɛɹts/ (US) · /hˈɜːts/ (UK) · CEFR C1 · Noun

Source: https://englishreference.com/word/hertz
Updated: 2026-08-15

## Definition

a unit used to measure how often something happens in one second. You usually see it when talking about sound waves, radio signals, or computer speeds.

For teachers: the SI unit of frequency, equal to one cycle per second. Named after Heinrich Hertz, it is used to quantify periodic phenomena such as electromagnetic waves and acoustic vibrations.

## Examples

- Human hearing usually ranges from 20 to 20,000 hertz.
- The technician adjusted the radio transmitter to broadcast at a specific frequency measured in hertz.
- Modern computer processors operate at billions of cycles per second, meaning their clock speeds are typically measured in gigahertz rather than simple hertz.

## Usage notes

- The word remains 'hertz' in both singular and plural forms; it does not take an 's' at the end for pluralization.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.