# ligand

/ˈɫɪɡənd/ (US) · CEFR C2 · Noun

Source: https://englishreference.com/word/ligand
Updated: 2026-05-09

## Definition

a molecule that binds to a specific site on a larger molecule, like a protein. This connection often sends a signal to a cell or causes a chemical change.

For teachers: a molecule or ion that binds specifically to a receptor or central metal atom to form a complex. In pharmacology, it acts as a signaling molecule that triggers a biological response upon binding.

## Examples

- The ligand attaches to the cell receptor.
- Researchers are developing a new ligand that can target cancer cells without affecting healthy tissue.
- The binding affinity of the ligand determines how effectively the drug can compete with natural hormones for the same receptor site within the nervous system.

## Usage notes

- Commonly used in biochemistry and pharmacology; often paired with the verb 'bind' and the preposition 'to'.

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