2Ecology an organism or species that comes to populate an ecosystem to which it is not native, usually to the detriment of those originally inhabiting the area.
Origin
1930s.
Definition of biological invader in US English:
biological invader
noun
1A pest or pathogen.
2Ecology an organism or species that comes to populate an ecosystem to which it is not native, usually to the detriment of those originally inhabiting the area.