desleal

Desleal is an adjective used in Portuguese to describe someone or something that lacks loyalty or acts in a treacherous, untrustworthy, or dishonest manner. It can refer to personal faithfulness, as in betrayal by a confidant or partner, or to conduct that violates duties, agreements, or expectations.

Etymology and related forms: The word is formed by the prefix des- (indicating negation) attached to leal, meaning loyal or faithful. The corresponding noun forms include deslealdade (the quality or state of being disloyal) and deslealismo, though deslealdade is the more common term for the concept.

Contexts and usage: Desleal is widely used across domains. In everyday language, it describes individuals who break trust or act deceitfully. In legal and regulatory contexts, phrases such as conduta desleal or concorrência desleal appear, referring to behavior that breaches loyalty obligations or constitutes unfair competition. In sports, desleal conduct denotes unsportsmanlike or unfair actions. The term often carries a moral judgment, signaling disapproval of betrayal or dishonesty.

Synonyms and antonyms: Synonyms include traidor, traiçoeiro, infiel, pérfido, and desleal can be contrasted with leal, fiel, sincero, and confiável (loyal, faithful, sincere, reliable). While related, leal emphasizes steadfast loyalty, whereas desleal emphasizes breach of that loyalty.

See also: Deslealdade, lealdade, concorrência desleal, conduta desleal.