# arsenic

/ˈɑɹsənɪk/ (US) · CEFR C1 · Noun

Source: https://englishreference.com/word/arsenic
Updated: 2026-05-07

## Definition

a chemical element that is famous for being a very strong poison. It is a greyish-silver metal that can be found in nature.

For teachers: a brittle, steel-grey metalloid element that is highly toxic in its inorganic forms. Often associated with historical toxicology and industrial processes.

## Examples

- The old pipes were tested for traces of arsenic.
- Environmental scientists monitored the groundwater near the old mine to ensure arsenic levels remained within safe limits.
- While arsenic is notoriously known as a potent poison in literature, it also has legitimate industrial applications in the strengthening of copper and lead alloys.

## Usage notes

- Uncountable when referring to the chemical element or the poison; can be countable in a chemistry context when referring to specific compounds.

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