Found 2 items, similar to fifth columnist.
English → English (WordNet) Definition: fifth columnist fifth columnist n : a member of a clandestine subversive organization who tries to help a potential invader [syn: saboteur]
English → English (gcide) Definition: fifth columnist columnist \col"um*nist\, n. a journalist who writes or edits a regularly scheduled column[8] in a periodical, usually in editorial style; a type of editorialist. [RP] fifth columnist see fifth columnist in the vocabulary.