a member of a clandestine subversive organization who tries to help a potential invader
The definition of a traitor is someone who betrays a country, cause or a friend.
A person who intentionally causes the destruction of property in order to hinder the efforts of his/her enemy.
Find another word for fifth-columnist. In this page you can discover 4 synonyms, antonyms, idiomatic expressions, and related words for fifth-columnist, like: quisling, traitor, saboteur and secret-agent.