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.