noun, masculine/tɾaiθjoˈneɾo/plural: traicioneros
traicionero is masculine in Spanish.
traitorous person
“No le creas, que ese personaje es un traicionero.” — Don't believe him; that character is traitorous.
Synonyms: traidor
From traición + -ero. According to Coromines and Pascual, attested since the 17th century.