The phrase "foreign intruders" refers to people or things from another country that enter or infiltrate a place where they are not wanted or do not belong. Full definition
At the edge of the plateau, rusty cannons are still in place, demonstrating the important role of Fort Louis in protecting the coast against foreign intruders. (jetblue.com)
Unlike foreign intruders such as bacteria, tumor cells are the patient's own and hence are less viciously attacked by the immune system. (sciencemag.org)
He still was not a neural engineer, but he was getting closer, because as it turns out, there is another really important thing to know about glia — they protect the brain from foreign intruders. (csne-erc.org)