تعريف fifth-columnist في الإنجليزية الإنجليزية القاموس.
person willing to cooperate with an aggressor against his own country, secret supporter of an enemy that engages in espionage or sabotage against his own country
a member of a clandestine subversive organization who tries to help a potential invader
A fifth columnist is someone who secretly supports and helps the enemies of the country or organization they are in. = traitor