| 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) |