1. In Platonic philosophy, an eternal, unchanging, abstract form or idea that represents the most accurate reality of a thing, of which physical objects are imperfect copies.
Usage: philosophy; formal; often capitalized when referring to Plato's theory
2. In phenomenology and later philosophy, the essential nature or structure of something as it appears to consciousness.
Usage: philosophy; formal

Examples

• Plato believed that the eidos of a chair exists beyond any individual chair we see in the physical world.
• According to Platonic theory, the eidos represents perfect, eternal forms that physical objects merely imitate.
• The philosopher argued that understanding the eidos of justice requires moving beyond particular examples of just acts.
• In Husserl's phenomenology, the eidos refers to the invariant essence revealed through careful observation of consciousness.
• The eidos of beauty, Plato suggested, cannot be fully captured by any single beautiful object.