CLDN
| Acronym | Definition |
|---|---|
| CLDN | Claudin (gene family) |
| CLDN | Canadian Lightning Detection Network (est. 1998; Environment Canada) |
| CLDN | Calling Line Directory Number |
| CLDN | Community Learning Disability Nurses (UK) |
| CLDN | Chronic Lung Disease of the Newborn (pediatrics) |