# mer

/ˈmɛɹ/ (US) · CEFR C2 · Noun

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

## Definition

a single unit or part that can join with others to form a long chain. Scientists use these small pieces to build larger structures called polymers.

For teachers: a single molecule that can undergo polymerisation, thereby contributing constitutional units to the essential structure of a macromolecule. Often used in technical contexts to describe the repeating structural unit of a polymer.

## Examples

- Each mer in the chain is identical to the next.
- The chemical properties of the resulting plastic depend heavily on the specific mer used during the synthesis process.
- By altering the arrangement of each individual mer within the copolymer, engineers can fine-tune the material's elasticity and thermal resistance for industrial applications.

## Usage notes

- Commonly appears as a suffix in terms like 'monomer', 'polymer', or 'isomer' rather than as a standalone word in general English.

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