Traiçoeiro

Traiçoeiro is a Portuguese adjective used to describe something or someone as treacherous, deceitful, or unreliable. It characterizes actions, behavior, or persons that betray trust, act with duplicity, or manage to mislead others. In some contexts it can function as a noun, referring to a person who behaves in such a way, though more common terms for a person are traidor or desleal.

Etymology and form: the word derives from the verb trair (to betray) and the suffix -eiro, which in Portuguese forms adjectives or agentive descriptors. It is closely related to the noun traição (betrayal) and shares semantic space with other pejoratives describing disloyal conduct. The adverbial form is traiçoeiramente.

Usage: traiçoeiro is used in formal and literary language as well as in journalism and discourse about relationships, politics, or business where trust is compromised. It emphasizes intentional deception or unreliability rather than mere error. Frequent collocations include comportamento traiçoeiro (treacherous behavior), ato traiçoeiro (treacherous act), and aliado traiçoeiro (treacherous ally). The term carries a strong negative connotation and can function as a warning or judgment about someone’s character.

See also: Traição, Traidor, Deslealdade, Traiçoeira can also appear in feminine form when describing a female subject, though the meaning remains the same.

In summary, traiçoeiro denotes treachery or deceitfulness, applicable to people or actions that undermine trust through duplicitous or unreliable conduct.