noun. 1. a viewable occurrence or physical one. 2. with regard to philosophy, something interpreted by the senses. With regard to Greek philosophy, most significantly that of Plato, phenomena are the logical things which make up the world of experience, as compared to the transcendent realities which are recognized only via reason. German philosopher Immanuel Kant utilized the word phenomena to reference things as they present to the senses and are perceived by the classes of the human perception.