The term 'THE X-FILES EXTRAS' refers to the actors and actresses who appeared in the popular science fiction television series The X-Files. The crossword solutions for this term are FEDS (4 letters), ETS (3 letters) and GMEN (4 letters). FEDS stands for Federal Bureau of Investigation, which is the law enforcement agency that the main characters of The X-Files worked for. ETS stands for Extra-Terrestrial Species, which is a reference to the aliens and other supernatural creatures featured in the show. GMEN stands for Government Men, which is a nickname for FBI agents.