Ethos is a term that refers to the distinguishing character, sentiment, moral nature, or guiding beliefs of a person, group, or institution. It is also a rhetorical or written technique that appeals to an audience or readers ethics, conveying the authors credibility and knowledge about the topic at hand. Ethos is one of the three "modes of persuasion" in rhetoric, along with logos and pathos.

To establish ethos, a speaker or writer must demonstrate that they are a trustworthy source of accurate information and have good moral character. Examples of ethos include citing credible sources, using professional titles, and demonstrating expertise in a particular field.

In summary, ethos is a term used to describe the character, beliefs, and guiding principles of a person, group, or institution, as well as a rhetorical technique used to establish credibility and trustworthiness with an audience or reader.