Definition of "exogenous"

Having an external cause.

1. (biology) Produced or originating outside of an organism.

2. (biology) Growing as an exogen, by successive additions to the outside.

3. (medicine, of a disease) Having a cause external to the infected organism.  examples

4. (economics, of a model) Being or relating to a change that comes from outside the model and is not explained by the model.  examples

5. (databases, of a key) Having no meaning in itself, such as an automatically generated sequential identifier.  examples

(biology, dermatology, uncommon) Related to the exogen growth phase.