# pico

/ˈpikoʊ/ (US)

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

## Senses

### 2. scientific prefix

noun · CEFR C1 · Technical

a prefix used in science and math to mean one trillionth (a very, very small part) of something.

For teachers: a metric prefix in the International System of Units (SI) denoting a factor of 10⁻¹² or one trillionth.

- The scientist measured the liquid in picolitres because the amount was so small.
- The sensor is capable of detecting electrical changes at the picofarad level, making it ideal for high-precision laboratory experiments.

## Examples

- The computer chip processes data in pico seconds.
- Engineers measured the electrical charge in picocoulombs to ensure the sensitive equipment would not malfunction.
- In modern physics, measuring intervals at the pico scale requires specialized lasers capable of emitting pulses that last only a trillionth of a second.

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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.