Pronunciation: (plāt'n-iz"um),[key] —n. 1. the philosophy or doctrines of Plato or his followers.
2. a Platonic doctrine or saying.
3. the belief that physical objects are impermanent representations of unchanging Ideas, and that the Ideas alone give true knowledge as they are known by the mind.
4. (sometimes l.c.) the doctrine or practice of platonic love.