exogenous
/ˌɛksɒˈdʒɛnəs/ or /ˌɛksɒˈdʒɛnəsɪs/Definitions
1. adjective
originating from outside; coming from outside an organism or system
“The exogenous factors contributing to climate change are numerous and complex.”
2. noun
an external substance or factor that affects an organism or system
“The bacteria responded to the exogenous stress by adapting quickly.”