2. Noun. (philosophy phenomenology Kantianism) The conscious self which is the unifying subject of a person's experiences and which cannot itself be experienced as an object, understood by Immanuel Kant (1724-1804) as knowable only by inference, and understood by Edmund Husserl (1859-1938) as pure consciousness. ¹
3. Noun. (alternative form of transcendental ego) ¹
¹ Source: wiktionary.com